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Background: SARS-CoV-2 variants of concern (VOCs) emerged and rapidly replaced the original strain worldwide. The increased transmissibility of these new variants led to increases in infections, hospitalizations, and mortality. However, there is a scarcity of retrospective investigations examining the severity of all the main VOCs in presence of key public health measures and within various social determinants of health (SDOHs)., Objective: This study aims to provide a retrospective assessment of the clinical severity of COVID-19 VOCs in the context of heterogenous SDOHs and vaccination rollout., Methods: We used a population-based retrospective cohort design with data from the British Columbia COVID-19 Cohort, a linked provincial surveillance platform. To assess the relative severity (hospitalizations, intensive care unit [ICU] admissions, and deaths) of Gamma, Delta, and Omicron infections during 2021 relative to Alpha, we used inverse probability treatment weighted Cox proportional hazard modeling. We also conducted a subanalysis among unvaccinated individuals, as assessed severity differed across VOCs and SDOHs., Results: We included 91,964 individuals infected with a SARS-CoV-2 VOC (Alpha: n=20,487, 22.28%; Gamma: n=15,223, 16.55%; Delta: n=49,161, 53.46%; and Omicron: n=7093, 7.71%). Delta was associated with the most severe disease in terms of hospitalization, ICU admissions, and deaths (hospitalization: adjusted hazard ratio [aHR] 2.00, 95% CI 1.92-2.08; ICU: aHR 2.05, 95% CI 1.91-2.20; death: aHR 3.70, 95% CI 3.23-4.25 relative to Alpha), followed generally by Gamma and then Omicron and Alpha. The relative severity by VOC remained similar in the unvaccinated individual subanalysis, although the proportion of individuals infected with Delta and Omicron who were hospitalized was 2 times higher in those unvaccinated than in those fully vaccinated. Regarding SDOHs, the proportion of hospitalized individuals was higher in areas with lower income across all VOCs, whereas among Alpha and Gamma infections, 2 VOCs that cocirculated, differential distributions of hospitalizations were found among racially minoritized groups., Conclusions: Our study provides robust severity estimates for all VOCs during the COVID-19 pandemic in British Columbia, Canada. Relative to Alpha, we found Delta to be the most severe, followed by Gamma and Omicron. This study highlights the importance of targeted testing and sequencing to ensure timely detection and accurate estimation of severity in emerging variants. It further sheds light on the importance of vaccination coverage and SDOHs in the context of pandemic preparedness to support the prioritization of allocation for resource-constrained or minoritized groups., (©Sean P Harrigan, Héctor A Velásquez García, Younathan Abdia, James Wilton, Natalie Prystajecky, John Tyson, Chris Fjell, Linda Hoang, Jeffrey C Kwong, Sharmistha Mishra, Linwei Wang, Beate Sander, Naveed Z Janjua, Hind Sbihi. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 27.08.2024.)

The mechanisms facilitating the relationship between low income and COVID-19 severity have not been partitioned in the presence of SARS-CoV-2 variants of concern (VOC). To address this, we used causal mediation analysis to quantify the possible mediating role infection with VOC has on the relationship between neighbourhood income (exposure) and hospitalisation due to COVID-19 among cases (outcome). A population-based cohort of 65,629 individuals residing in British Columbia, Canada, was divided into three periods of VOC co-circulation in the 2021 calendar year whereby each period included co-circulation of an emerging and an established VOC. Each cohort was subjected to g-formula mediation techniques to decompose the relationship between exposure and outcome into total, direct and indirect effects. In the mediation analysis, the total effects indicated that low income was associated with increased odds of hospitalisation across all periods. Further decomposition of the effects revealed that income is directly and indirectly associated with hospitalisation. The resulting indirect effect through VOC accounted for approximately between 6 and 13% of the total effect of income on hospitalisation. This study underscores, conditional on the analysis, the importance of addressing underlying inequities to mitigate the disproportionate impact on historically marginalised communities by adopting an equity lens as central to pandemic preparedness and response from the onset., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.)

Background: Most working-age (18-64) adults have been infected with SARS-CoV-2, and some may have developed post-COVID-19 condition (PCC). However, long-term health-related quality of life (HRQOL) following infection remains uncharacterized., Methods: In this cross-sectional study, COVID-19 survivors from throughout British Columbia (BC), Canada, completed a questionnaire >2 years after infection. PCC status was self-reported, and HRQOL was assessed using the EuroQol 5-dimension 5-level (EQ-5D-5L) instrument. We compared HRQOL in those with current PCC, those with recovered PCC, and those without a history of PCC. Multivariable analyses were weighted to be representative of COVID-19 survivors in BC., Results: Of the 1,135 analyzed participants, 19.2% had current PCC, and 27.6% had recovered PCC. Compared to those without a history of PCC, participants with recovered PCC had a similar mean EQ-5D health utility (adjusted difference -0.02 [95%CI -0.03, 0.00]), but those with current PCC had a lower health utility (adjusted difference -0.08 [95%CI -0.12, -0.05]). Participants with current PCC were also more likely to report problems with mobility (adjusted odds ratio (aOR) 6.00 [95%CI 2.88-12.52]), self-care (aOR 5.96 [95%CI 1.84-19.32]), usual activities (aOR 8.00 [95%CI 4.27-14.99]), pain/discomfort (aOR 4.28 [95%CI 2.46-7.48]), and anxiety/depression (aOR 3.45 [95%CI 1.90-6.27])., Conclusions: In working-age adults who have survived >2 years following COVID-19, HRQOL is high among those who never had PCC or have recovered from PCC. However, individuals with ongoing symptoms have lower HRQOL and are more likely to have functional deficits. These findings underscore the importance of implementing targeted healthcare interventions to improve HRQOL in adults with long-term PCC., (Copyright © 2024. Published by Elsevier Inc.)

Background: COVID-19 is associated with increased risk of post-acute cardiovascular outcomes. Population-based evidence for long periods of observation is still limited., Methods: This population-based cohort study was conducted using data (2020-2021) from the British Columbia COVID-19 Cohort. The exposure of interest was severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, identified through reverse transcription-polymerase chain reaction (RT-PCR) assay. Individuals who tested positive (exposed) on RT-PCR were matched to negative controls (unexposed) on sex, age, and RT-PCR collection date in a 1:4 ratio. Outcomes of interest were incident major adverse cardiovascular events and acute myocardial infarction, identified more than 30 days after RT-PCR collection date. The association between SARS-CoV-2 infection and cardiovascular risk was assessed through multivariable survival models. Population attributable fractions were computed from Cox models., Results: We included 649,320 individuals: 129,864 exposed and 519,456 unexposed. The median duration of follow-up was 260 days; 1,786 events (0.34%) took place among the unexposed, and 702 (0.54%) in the exposed. The risk of major adverse cardiovascular events was higher in the exposed (adjusted hazard ratio [aHR] 1.34; 95% confidence interval [CI], 1.22-1.46), with greater risk observed in those who were hospitalized (aHR 3.81; 95% CI, 3.12-4.65) or required intensive care unit admission (aHR 6.25; 95% CI, 4.59-8.52) compared with the unexposed group. The fraction of cardiovascular events attributable to SARS-CoV-2 was 7.04% (95% CI, 4.67-9.41%). Comparable results were observed for acute myocardial infarction., Conclusions: SARS-CoV-2 infection was associated with higher cardiovascular risk, with graded increase across the acute COVID-19 severity, contributing to 7% of incident major adverse cardiovascular events. These findings suggest that long-term monitoring of cardiovascular risk is required in COVID-19 survivors., (Copyright © 2024. Published by Elsevier Inc.)

We assessed the association between cirrhosis and severe COVID-19-related outcomes among people with laboratory-diagnosed COVID-19 infection in British Columbia, Canada. We used data from the British Columbia (BC) COVID-19 Cohort, a population-based cohort that integrates data on all individuals tested for COVID-19, with data on hospitalizations, medical visits, emergency room visits, prescription drugs, chronic conditions, and deaths in the Canadian province of BC. We included all individuals aged ≥18 who tested positive for SARS-CoV-2 by real-time reverse transcription-polymerase chain reaction from 1 January 2021 to 31 December 2021. Multivariable logistic regression models were used to assess the associations of cirrhosis status with COVID-19-related hospitalization and with ICU admission. Of the 162,509 individuals who tested positive for SARS-CoV-2 and were included in the analysis, 768 (0.5%) had cirrhosis. In the multivariable models, cirrhosis was associated with increased odds of hospitalization (aOR = 1.97, 95% CI: 1.58-2.47) and ICU admission (aOR = 3.33, 95% CI: 2.56-4.35). In the analyses stratified by age, we found that the increased odds of ICU admission among people with cirrhosis were present in all the assessed age-groups. Cirrhosis is associated with increased odds of hospitalization and ICU admission among COVID-19 patients.

Purpose: The British Columbia COVID-19 Cohort (BCC19C) was developed from an innovative, dynamic surveillance platform and is accessed/analyzed through a cloud-based environment. The platform integrates recently developed provincial COVID-19 datasets (refreshed daily) with existing administrative holdings and provincial registries (refreshed weekly/monthly). The platform/cohort were established to inform the COVID-19 response in near "real-time" and to answer more in-depth epidemiologic questions., Participants: The surveillance platform facilitates the creation of large, up-to-date analytic cohorts of people accessing COVID-19 related services and their linked medical histories. The program of work focused on creating/analyzing these cohorts is referred to as the BCC19C. The administrative/registry datasets integrated within the platform are not specific to COVID-19 and allow for selection of "control" individuals who have not accessed COVID-19 services., Findings to Date: The platform has vastly broadened the range of COVID-19 analyses possible, and outputs from BCC19C analyses have been used to create dashboards, support routine reporting and contribute to the peer-reviewed literature. Published manuscripts (total of 15 as of July, 2023) have appeared in high-profile publications, generated significant media attention and informed policy and programming. In this paper, we conducted an analysis to identify sociodemographic and health characteristics associated with receiving SARS-CoV-2 laboratory testing, testing positive, and being fully vaccinated. Other published analyses have compared the relative clinical severity of different variants of concern; quantified the high "real-world" effectiveness of vaccines in addition to the higher risk of myocarditis among younger males following a 2nd dose of an mRNA vaccine; developed and validated an algorithm for identifying long-COVID patients in administrative data; identified a higher rate of diabetes and healthcare utilization among people with long-COVID; and measured the impact of the pandemic on mental health, among other analyses., Future Plans: While the global COVID-19 health emergency has ended, our program of work remains robust. We plan to integrate additional datasets into the surveillance platform to further improve and expand covariate measurement and scope of analyses. Our analyses continue to focus on retrospective studies of various aspects of the COVID-19 pandemic, as well as prospective assessment of post-acute COVID-19 conditions and other impacts of the pandemic., Competing Interests: NJ reported receiving personal fees from Gilead and AbbVie outside the submitted work. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wilton, Abdulmenan, Chong, Becerra, Najmul Hussain, Harrigan, Velásquez García, Naveed, Sbihi, Smolina, Taylor, Adhikari, Zandy, Setayeshgar, Li, Abdia, Binka, Rasali, Rose, Coss, Flatt, Mussavi Rizi and Janjua.)

Objective: To compare myocarditis/pericarditis risk after COVID-19 mRNA vaccination versus SARS-CoV-2 infection, and to assess if myocarditis/pericarditis risk varies by vaccine dosing interval., Methods: In this retrospective cohort study, we used linked databases in Quebec, Ontario, and British Columbia between January 26, 2020, and September 9, 2021. We included individuals aged 12 or above who received an mRNA vaccine as the second dose or were SARS-CoV-2-positive by RT-PCR. The outcome was hospitalization/emergency department visit for myocarditis/pericarditis within 21 days of exposure. We calculated age- and sex-stratified incidence ratios (IRs) of myocarditis/pericarditis following mRNA vaccination versus SARS-CoV-2 infection. We also calculated myocarditis/pericarditis incidence by vaccine type, homologous/heterologous schedule, and dosing interval. We pooled province-specific estimates using meta-analysis., Results: Following 18,860,817 mRNA vaccinations and 860,335 SARS-CoV-2 infections, we observed 686 and 160 myocarditis/pericarditis cases, respectively. Myocarditis/pericarditis incidence was lower after vaccination than infection (IR [BNT162b2/SARS-CoV-2], 0.14; 95%CI, 0.07-0.29; IR [mRNA-1273/SARS-CoV-2], 0.28; 95%CI, 0.20-0.39). Within the vaccinated cohort, myocarditis/pericarditis incidence was lower with longer dosing intervals; IR (56 or more days/15-30 days) was 0.28 (95%CI, 0.19-0.41) for BNT162b2 and 0.26 (95%CI, 0.18-0.38) for mRNA-1273., Conclusion: Myocarditis/pericarditis risk was lower after mRNA vaccination than SARS-CoV-2 infection, and with longer intervals between primary vaccine doses., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Naveed Z. Janjua reports a relationship with 10.13039/100006483AbbVie Inc that includes: consulting or advisory and speaking and lecture fees. Naveed Z. Janjua reports a relationship with 10.13039/100005564Gilead Sciences that includes: consulting or advisory and speaking and lecture fees. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2024 Published by Elsevier Ltd.)

Background: Racialized populations in the United States, Canada, and the United Kingdom have been disproportionately affected by COVID-19. Higher vaccine hesitancy has been reported among racial and ethnic minorities in some of these countries. In the United Kingdom, for example, higher vaccine hesitancy has been observed among the South Asian population and Black compared with the White population, and this has been attributed to lack of trust in government due to historical and ongoing racism and discrimination., Objective: This study aimed to assess vaccine receipt by ethnicity and its relationship with mistrust among ethnic groups in British Columbia (BC), Canada., Methods: We included adults ≥18 years of age who participated in the BC COVID-19 Population Mixing Patterns Survey (BC-Mix) from March 8, 2021, to August 8, 2022. The survey included questions about vaccine receipt and beliefs based on a behavioral framework. Multivariable logistic regression was used to assess the association between mistrust in vaccines and vaccine receipt among ethnic groups., Results: The analysis included 25,640 adults. Overall, 76.7% (22,010/28,696) of respondents reported having received at least 1 dose of COVID-19 vaccines (Chinese=86.1%, South Asian=79.6%, White=75.5%, and other ethnicity=73.2%). Overall, 13.7% (3513/25,640) of respondents reported mistrust of COVID-19 vaccines (Chinese=7.1%, South Asian=8.2%, White=15.4%, and other ethnicity=15.2%). In the multivariable model (adjusting for age, sex, ethnicity, educational attainment, and household size), mistrust was associated with a 93% reduced odds of vaccine receipt (adjusted odds ratio 0.07, 95% CI 0.06-0.08). In the models stratified by ethnicity, mistrust was associated with 81%, 92%, 94%, and 95% reduced odds of vaccine receipt among South Asian, Chinese, White, and other ethnicities, respectively. Indecision, whether to trust the vaccine or not, was significantly associated with a 70% and 78% reduced odds of vaccine receipt among those who identified as White and of other ethnic groups, respectively., Conclusions: Vaccine receipt among those who identified as South Asian and Chinese in BC was higher than that among the White population. Vaccine mistrust was associated with a lower odds of vaccine receipt in all ethnicities, but it had a lower effect on vaccine receipt among the South Asian and Chinese populations. Future research needs to focus on sources of mistrust to better understand its potential influence on vaccine receipt among visible minorities in Canada., (©Bushra Mahmood, Prince Adu, Geoffrey McKee, Aamir Bharmal, James Wilton, Naveed Zafar Janjua. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 16.02.2024.)

Competing Interests: The authors have no financial interest to declare in relation to the content of this article.

Introduction: People living with HIV (PLWH) and/or who inject drugs may experience lower vaccine effectiveness (VE) against SARS-CoV-2 infection., Methods: A validated algorithm was applied to population-based, linked administrative datasets in the British Columbia COVID-19 Cohort (BCC19C) to ascertain HIV status and create a population of PLWH and matched HIV-negative individuals. The study population was limited to individuals who received an RT-PCR laboratory test for SARS-CoV-2 between 15 December 2020 and 21 November 2021 in BC, Canada. Any history of injection drug use (IDU) was ascertained using a validated administrative algorithm. We used a test-negative study design (modified case-control analysis) and multivariable logistic regression to estimate adjusted VE by HIV status and history of IDU., Results: Our analysis included 2700 PLWH and a matched population of 375,043 HIV-negative individuals, among whom there were 351 and 103,049 SARS-CoV-2 cases, respectively. The proportion of people with IDU history was much higher among PLWH compared to HIV-negative individuals (40.7% vs. 4.3%). Overall VE during the first 6 months after second dose was lower among PLWH with IDU history (65.8%, 95% CI = 43.5-79.3) than PLWH with no IDU history (80.3%, 95% CI = 62.7-89.6), and VE was particularly low at 4-6 months (42.4%, 95% CI = -17.8 to 71.8 with IDU history vs. 64.0%; 95% CI = 15.7-84.7 without), although confidence intervals were wide. In contrast, overall VE was 88.6% (95% CI = 88.2-89.0) in the matched HIV-negative population with no history of IDU and remained relatively high at 4-6 months after second dose (84.6%, 95% CI = 83.8-85.4). Despite different patterns of vaccine protection by HIV status and IDU history, peak estimates were similar (≥88%) across all populations., Conclusions: PLWH with a history of IDU may experience lower VE against COVID-19 infection, although findings were limited by a small sample size. The lower VE at 4-6 months may have implications for booster dose prioritization for PLWH and people who inject drugs. The immunocompromising effect of HIV, substance use and/or co-occurring comorbidities may partly explain these findings., (© 2023 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of International AIDS Society.)

Objective: To examine the risk of hospitalization within 14 days of COVID-19 diagnosis among people living with HIV (PLWH) and HIV-negative individuals who had laboratory-confirmed SARS-CoV-2 infection., Methods: We used Cox proportional hazard models to compare the relative risk of hospitalization in PLWH and HIV-negative individuals. Then, we used propensity score weighting to examine the influence of sociodemographic factors and comorbid conditions on risk of hospitalization. These models were further stratified by vaccination status and pandemic period (pre-Omicron: December 15, 2020, to November 21, 2021; Omicron: November 22, 2021, to October 31, 2022)., Results: The crude hazard ratio (HR) for risk of hospitalization in PLWH was 2.44 (95% confidence interval [CI]: 2.04-2.94). In propensity score-weighted models that included all covariates, the relative risk of hospitalization was substantially attenuated in the overall analyses (adjusted HR [aHR]: 1.03; 95% CI: 0.85-1.25), in vaccinated (aHR 1.00; 95% CI: 0.69-1.45), inadequately vaccinated (aHR: 1.04; 95% CI: 0.76-1.41) and unvaccinated individuals (aHR: 1.15; 95% CI: 0.84-1.56)., Conclusion: PLWH had about two times the risk of COVID-19 hospitalization than HIV-negative individuals in crude analyses which attenuated in propensity score-weighted models. This suggests that the risk differential can be explained by sociodemographic factors and history of comorbidity, underscoring the need to address social and comorbid vulnerabilities (e.g., injecting drugs) that were more prominent among PLWH., Competing Interests: Declarations of competing interest The authors have no competing interests to declare., (Copyright © 2023. Published by Elsevier Ltd.)

Objectives: We aimed to estimate the rate of myocarditis after the messenger RNA (mRNA) COVID-19 booster vaccination by vaccine type, age, and sex., Methods: We used data from the British Columbia COVID-19 Cohort, a population-based cohort surveillance platform. The exposure was a booster dose of an mRNA vaccine. The outcome was diagnosis of myocarditis during hospitalization or an emergency department visit within 7-21 days of booster vaccination., Results: The overall rate of myocarditis was lower for the booster dose (6.41, 95% confidence interval [CI]: 3.50-10.75) than the second dose (17.97, 95% CI: 13.78-23.04); (Rate ratio booster vs dose-2  = 0.34, 95% CI: 0.17-0.61). This difference was more apparent for the mRNA-1273 vaccine type. After the second dose, the myocarditis rate in males was significantly lower for BNT162b2 than mRNA-1273 overall and among those aged 18-39 years. In contrast, after the booster dose, no significant differences between myocarditis and vaccine type was observed overall or within the specific age groups among males or females., Conclusion: Myocarditis after mRNA COVID-19 vaccines is a rare event. A lower absolute risk of myocarditis was observed after a booster dose of mRNA vaccine than the primary series second dose., Competing Interests: Declarations of competing interest NZJ participated in advisory boards and has spoken for AbbVie and Gilead, not related to current work. The other authors have no competing interests to declare., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Importance: SARS-CoV-2 infection may lead to acute and chronic sequelae. Emerging evidence suggests a higher risk of diabetes after infection, but population-based evidence is still sparse., Objective: To evaluate the association between COVID-19 infection, including severity of infection, and risk of diabetes., Design, Setting, and Participants: This population-based cohort study was conducted in British Columbia, Canada, from January 1, 2020, to December 31, 2021, using the British Columbia COVID-19 Cohort, a surveillance platform that integrates COVID-19 data with population-based registries and administrative data sets. Individuals tested for SARS-CoV-2 by real-time reverse transcription-polymerase chain reaction (RT-PCR) were included. Those who tested positive for SARS-CoV-2 (ie, those who were exposed) were matched on sex, age, and collection date of RT-PCR test at a 1:4 ratio to those who tested negative (ie, those who were unexposed). Analysis was conducted January 14, 2022, to January 19, 2023., Exposure: SARS-CoV-2 infection., Main Outcomes and Measures: The primary outcome was incident diabetes (insulin dependent or not insulin dependent) identified more than 30 days after the specimen collection date for the SARS-CoV-2 test with a validated algorithm based on medical visits, hospitalization records, chronic disease registry, and prescription drugs for diabetes management. Multivariable Cox proportional hazard modeling was performed to evaluate the association between SARS-CoV-2 infection and diabetes risk. Stratified analyses were performed to assess the interaction of SARS-CoV-2 infection with diabetes risk by sex, age, and vaccination status., Results: Among 629 935 individuals (median [IQR] age, 32 [25.0-42.0] years; 322 565 females [51.2%]) tested for SARS-CoV-2 in the analytic sample, 125 987 individuals were exposed and 503 948 individuals were unexposed. During the median (IQR) follow-up of 257 (102-356) days, events of incident diabetes were observed among 608 individuals who were exposed (0.5%) and 1864 individuals who were not exposed (0.4%). The incident diabetes rate per 100 000 person-years was significantly higher in the exposed vs nonexposed group (672.2 incidents; 95% CI, 618.7-725.6 incidents vs 508.7 incidents; 95% CI, 485.6-531.8 incidents; P < .001). The risk of incident diabetes was also higher in the exposed group (hazard ratio [HR], 1.17; 95% CI, 1.06-1.28) and among males (adjusted HR, 1.22; 95% CI, 1.06-1.40). The risk of diabetes was higher among people with severe disease vs those without COVID-19, including individuals admitted to the intensive care unit (HR, 3.29; 95% CI, 1.98-5.48) or hospital (HR, 2.42; 95% CI, 1.87-3.15). The fraction of incident diabetes cases attributable to SARS-CoV-2 infection was 3.41% (95% CI, 1.20%-5.61%) overall and 4.75% (95% CI, 1.30%-8.20%) among males., Conclusions and Relevance: In this cohort study, SARS-CoV-2 infection was associated with a higher risk of diabetes and may have contributed to a 3% to 5% excess burden of diabetes at a population level.

Background: In late 2021, the Omicron severe acute respiratory syndrome coronavirus 2 variant emerged and rapidly replaced Delta as the dominant variant. The increased transmissibility of Omicron led to surges in case rates and hospitalizations; however, the true severity of the variant remained unclear. We aimed to provide robust estimates of Omicron severity relative to Delta., Methods: This retrospective cohort study was conducted with data from the British Columbia COVID-19 Cohort, a large provincial surveillance platform with linkage to administrative datasets. To capture the time of cocirculation with Omicron and Delta, December 2021 was chosen as the study period. Whole-genome sequencing was used to determine Omicron and Delta variants. To assess the severity (hospitalization, intensive care unit [ICU] admission, length of stay), we conducted adjusted Cox proportional hazard models, weighted by inverse probability of treatment weights (IPTW)., Results: The cohort was composed of 13 128 individuals (7729 Omicron and 5399 Delta). There were 419 coronavirus disease 2019 hospitalizations, with 118 (22%) among people diagnosed with Omicron (crude rate = 1.5% Omicron, 5.6% Delta). In multivariable IPTW analysis, Omicron was associated with a 50% lower risk of hospitalization compared with Delta (adjusted hazard ratio [aHR] = 0.50, 95% confidence interval [CI] = 0.43 to 0.59), a 73% lower risk of ICU admission (aHR = 0.27, 95% CI = 0.19 to 0.38), and a 5-day shorter hospital stay (aß = -5.03, 95% CI = -8.01 to -2.05)., Conclusions: Our analysis supports findings from other studies that have demonstrated lower risk of severe outcomes in Omicron-infected individuals relative to Delta., Competing Interests: Potential conflicts of interest . M. K. has grants and contracts with AbCellera (contract paid to institution), Roche, Hologic (contract paid to institution), and Siemens (contract paid to institution), all of which are unrelated to this study. N. Z. J. participates in an AbbVie Advisory Board meeting; reports payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from AbbVie; and reports grants or contracts unrelated to this work from the Canadian Institutes of Health Research, Michael Smith Foundation for Health Research, and Public Health Agency of Canada. H. S. reports grants or contracts unrelated to this work from the Canadian Institutes for Health Research. N. P. reports grants or contracts unrelated to this work from the Canadian Institutes for Health Research and Michael Smith Foundation for Health Research. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: We compared the population rate of COVID-19 and influenza hospitalisations by age, COVID-19 vaccine status and pandemic phase, which was lacking in other studies., Method: We conducted a population-based study using hospital data from the province of British Columbia (population 5.3 million) in Canada with universal healthcare coverage. We created two cohorts of COVID-19 hospitalisations based on date of admission: annual cohort (March 2020 to February 2021) and peak cohort (Omicron era; first 10 weeks of 2022). For comparison, we created influenza annual and peak cohorts using three historical periods years to capture varying severity and circulating strains: 2009/2010, 2015/2016 and 2016/2017. We estimated hospitalisation rates per 100 000 population., Results: COVID-19 and influenza hospitalisation rates by age group were 'J' shaped. The population rate of COVID-19 hospital admissions in the annual cohort (mostly unvaccinated; public health restrictions in place) was significantly higher than influenza among individuals aged 30-69 years, and comparable to the severe influenza year (2016/2017) among 70+. In the peak COVID-19 cohort (mostly vaccinated; few restrictions in place), the hospitalisation rate was comparable with influenza 2016/2017 in all age groups, although rates among the unvaccinated population were still higher than influenza among 18+. Among people aged 5-17 years, COVID-19 hospitalisation rates were lower than/comparable to influenza years in both cohorts. The COVID-19 hospitalisation rate among 0-4 years old, during Omicron, was higher than influenza 2015/2016 and 2016/2017 and lower than 2009/2010 pandemic., Conclusions: During first Omicron wave, COVID-19 hospitalisation rates were significantly higher than historical influenza hospitalisation rates for unvaccinated adults but were comparable to influenza for vaccinated adults. For children, in the context of high infection levels, hospitalisation rates for COVID-19 were lower than 2009/2010 H1N1 influenza and comparable (higher for 0-4) to non-pandemic years, regardless of the vaccine status., Competing Interests: Competing interests: NJ reports having received grants from Canadian Institutes of Health Research, Michael Smith Foundation for Health Research, and Public Health Agency of Canada, unrelated to this work. He also declares receiving payment/honoraria from AbbVie, unrelated to this work., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: We estimated the effectiveness of COVID-19 vaccines against laboratory-confirmed SARS-CoV-2 infection among people living with HIV (PLWH) and compared the estimates with a matched HIV-negative cohort., Methods: We used the British Columbia COVID-19 Cohort, a population-based data platform, which integrates COVID-19 data on SARS-CoV-2 tests, laboratory-confirmed cases, and immunizations with provincial health services data. The vaccine effectiveness (VE) was estimated with a test-negative design using the multivariable logistic regression., Results: The adjusted VE against SARS-CoV-2 infection was 71.1% (39.7, 86.1%) 7-59 days after two doses, rising to 89.3% (72.2, 95.9%) between 60 and 89 days. VE was preserved 4-6 months after the receipt of two doses, after which noticeable waning was observed (51.3% [4.8, 75.0%]). In the matched HIV-negative cohort (n = 375,043), VE peaked at 91.4% (90.9, 91.8%) 7-59 days after two doses and was sustained for up to 4 months, after which evidence of waning was observed, dropping to 84.2% (83.4, 85.0%) between 4 and 6 months., Conclusion: The receipt of two COVID-19 vaccine doses was effective against SARS-CoV-2 infection among PLWH pre-Omicron. VE estimates appeared to peak later in PLWH than in the matched HIV-negative cohort and the degree of waning was relatively quicker in PLWH; however, peak estimates were comparable in both populations., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: With the uptake of COVID-19 vaccines, there is a need for population-based studies to assess risk factors for COVID-19-related hospitalization after vaccination and how they differ from unvaccinated individuals., Methods: We used data from the British Columbia COVID-19 Cohort, a population-based cohort that includes all individuals (aged ≥18 years) who tested positive for SARS-CoV-2 by real-time reverse transcription-polymerase chain reaction from January 1, 2021 (after the start of vaccination program) to December 31, 2021. We used multivariable logistic regression models to assess COVID-19-related hospitalization risk by vaccination status and age group among confirmed COVID-19 cases., Results: Of the 162,509 COVID-19 cases included in the analysis, 8,546 (5.3%) required hospitalization. Among vaccinated individuals, an increased odds of hospitalization with increasing age was observed for older age groups, namely those aged 50-59 years (odds ratio [OR] = 2.95, 95% confidence interval [CI]: 2.01-4.33), 60-69 years (OR = 4.82, 95% CI: 3.29, 7.07), 70-79 years (OR = 11.92, 95% CI: 8.02, 17.71), and ≥80 years (OR = 24.25, 95% CI: 16.02, 36.71). However, among unvaccinated individuals, there was a graded increase in odds of hospitalization with increasing age, starting at age group 30-39 years (OR = 2.14, 95% CI: 1.90, 2.41) to ≥80 years (OR = 41.95, 95% CI: 35.43, 49.67). Also, comparing all the age groups to the youngest, the observed magnitude of association was much higher among unvaccinated individuals than vaccinated ones., Conclusion: Alongside a number of comorbidities, our findings showed a strong association between age and COVID-19-related hospitalization, regardless of vaccination status. However, age-related hospitalization risk was reduced two-fold by vaccination, highlighting the need for vaccination in reducing the risk of severe disease and subsequent COVID-19-related hospitalization across all population groups., Competing Interests: Declaration of competing interest N.Z.J. participated in advisory boards for AbbVie and has spoken for AbbVie and Gilead not related to the current work. The other authors have no competing interests to declare., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Postmarketing evaluations have linked myocarditis to SARS-CoV-2 mRNA vaccines. We sought to estimate the incidence of myocarditis after mRNA vaccination against SARS-CoV-2, and to compare the incidence with expected rates based on historical background rates in British Columbia., Methods: We conducted an observational study using population health administrative data from the BC COVID-19 Cohort from Dec. 15, 2020, to Mar. 10, 2022. The primary exposure was any dose of an mRNA vaccine against SARS-CoV-2. The primary outcome was incidence of hospital admission or emergency department visit for myocarditis or myopericarditis within 7 and 21 days postvaccination, calculated as myocarditis rates per 100 000 mRNA vaccine doses, expected rates of myocarditis cases and observedto-expected ratios. We stratified analyses by age, sex, vaccine type and dose number., Results: We observed 99 incident cases of myocarditis within 7 days (0.97 cases per 100 000 vaccine doses; observed v. expected ratio 14.81, 95% confidence interval [CI] 10.83-16.55) and 141 cases within 21 days (1.37 cases per 100 000 vaccine doses; observed v. expected ratio 7.03, 95% CI 5.92-8.29) postvaccination. Cases of myocarditis per 100 000 vaccine doses were higher for people aged 12-17 years (2.64, 95% CI 1.54-4.22) and 18-29 years (2.63, 95% CI 1.94-3.50) than for older age groups, for males compared with females (1.64, 95% CI 1.30-2.04 v. 0.35, 95% CI 0.21-0.55), for those receiving a second dose compared with a third dose (1.90, 95% CI 1.50-2.39 v. 0.76, 95% CI 0.45-1.30) and for those who received the mRNA-1273 (Moderna) vaccine compared with the BNT162b2 (Pfizer-BioNTech) vaccine (1.44, 95% CI 1.06-1.91 v. 0.74, 95% CI 0.56-0.98). The highest observed-to-expected ratio was seen after the second dose among males aged 18-29 years who received the mRNA-1273 vaccine (148.32, 95% CI 95.03-220.69)., Interpretation: Although absolute rates of myocarditis were low, vaccine type, age and sex are important factors to consider when strategizing vaccine administration to reduce the risk of postvaccination myocarditis. Our findings support the preferential use of the BNT162b2 vaccine over the mRNA-1273 vaccine for people aged 18-29 years., Competing Interests: Competing interests: Naveed Zafar Janjua reports honoraria from AbbVie and Gilead, as well as participation on advisory boards with AbbVie, outside the submitted work. He also reports roles as coprincipal investigator and member of the steering committee with the Canadian Hepatitis C Network. No other competing interests were declared., (© 2022 CMA Impact Inc. or its licensors.)

Background: Postmarketing evaluations have linked myocarditis to COVID-19 mRNA vaccines. However, few population-based analyses have directly compared the safety of the 2 mRNA COVID-19 vaccines., Objectives: This study aimed to compare the risk of myocarditis, pericarditis, and myopericarditis between BNT162b2 and mRNA-1273., Methods: We used data from the British Columbia COVID-19 Cohort (BCC19C), a population-based cohort study. The exposure was the second dose of an mRNA vaccine. The outcome was diagnosis of myocarditis, pericarditis, or myopericarditis during a hospitalization or an emergency department visit within 21 days of the second vaccination dose. We performed multivariable logistic regression to assess the association between vaccine product and the outcomes of interest., Results: The rates of myocarditis and pericarditis per million second doses were higher for mRNA-1273 (n = 31, rate 35.6; 95% CI: 24.1-50.5; and n = 20, rate 22.9; 95% CI: 14.0-35.4, respectively) than BNT162b2 (n = 28, rate 12.6; 95% CI: 8.4-18.2 and n = 21, rate 9.4; 95% CI: 5.8-14.4, respectively). mRNA-1273 vs BNT162b2 had significantly higher odds of myocarditis (adjusted OR [aOR]: 2.78; 95% CI: 1.67-4.62), pericarditis (aOR: 2.42; 95% CI: 1.31-4.46) and myopericarditis (aOR: 2.63; 95% CI: 1.76-3.93). The association between mRNA-1273 and myocarditis was stronger for men (aOR: 3.21; 95% CI: 1.77-5.83) and younger age group (18-39 years; aOR: 5.09; 95% CI: 2.68-9.66)., Conclusions: Myocarditis/pericarditis following mRNA COVID-19 vaccines is rare, but we observed a 2- to 3-fold higher odds among individuals who received mRNA-1273 vs BNT162b2. The rate of myocarditis following mRNA-1273 receipt is highest among younger men (age 18-39 years) and does not seem to be present at older ages. Our findings may have policy implications regarding the choice of vaccine offered., Competing Interests: Funding Support and Author Disclosures This work was supported by the British Columbia Centre for Disease Control and the Canadian Immunization Research Network (CIRN) through a grant from the Public Health Agency of Canada and the Canadian Institutes of Health Research (CNF 151944). This project was also supported by funding from the Public Health Agency of Canada through the Vaccine Surveillance Reference Group and the COVID-19 Immunity Task Force. All inferences, opinions, and conclusions drawn in this paper are those of the authors and do not reflect the opinions or policies of the Data Steward(s). Dr Kwong is supported by a Clinician-Scientist Award from the University of Toronto Department of Family and Community Medicine. Dr Janjua has participated in advisory boards and has spoken for AbbVie, not related to the current work. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: Several non-pharmaceutical interventions, such as physical distancing, handwashing, self-isolation, and school and business closures, were implemented in British Columbia (BC) following the first laboratory-confirmed case of COVID-19 on 26 January 2020, to minimise in-person contacts that could spread infections. The BC COVID-19 Population Mixing Patterns Survey (BC-Mix) was established as a surveillance system to measure behaviour and contact patterns in BC over time to inform the timing of the easing/re-imposition of control measures. In this paper, we describe the BC-Mix survey design and the demographic characteristics of respondents., Participants: The ongoing repeated online survey was launched in September 2020. Participants are mainly recruited through social media platforms (including Instagram, Facebook, YouTube, WhatsApp). A follow-up survey is sent to participants 2-4 weeks after completing the baseline survey. Survey responses are weighted to BC's population by age, sex, geography and ethnicity to obtain generalisable estimates. Additional indices such as the Material and Social Deprivation Index, residential instability, economic dependency, and others are generated using census and location data., Findings to Date: As of 26 July 2021, over 61 000 baseline survey responses were received of which 41 375 were eligible for analysis. Of the eligible participants, about 60% consented to follow-up and about 27% provided their personal health numbers for linkage with healthcare databases. Approximately 83.5% of respondents were female, 58.7% were 55 years or older, 87.5% identified as white and 45.9% had at least a university degree. After weighting, approximately 50% were female, 39% were 55 years or older, 65% identified as white and 50% had at least a university degree., Future Plans: Multiple papers describing contact patterns, physical distancing measures, regular handwashing and facemask wearing, modelling looking at impact of physical distancing measures and vaccine acceptance, hesitancy and uptake are either in progress or have been published., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Evidence that opioid agonist therapy (OAT) is associated with increased odds of hepatitis C virus (HCV) treatment initiation among people who use drugs (PWUD) is emerging. The objective of this study was to determine the association between current OAT and HCV treatment initiation among PWUD in a population-level linked administrative dataset., Methods: The British Columbia Hepatitis Testers Cohort was used for this study, which includes all people tested for or diagnosed with HCV in British Columbia, linked to medical visits, hospitalizations, laboratory, prescription drug, and mortality data from 1992 until 2019. PWUD with injecting drug use or opioid use disorder and chronic HCV infection were identified for inclusion in this study. HCV treatment initiation was the main outcome, and subdistribution proportional hazards modeling was used to assess the relationship with current OAT., Results: In total, 13 803 PWUD with chronic HCV were included in this study. Among those currently on OAT at the end of the study period, 47% (2704/5770) had started HCV treatment, whereas 22% (1778/8033) of those not currently on OAT had started HCV treatment. Among PWUD with chronic HCV infection, current OAT was associated with higher likelihood of HCV treatment initiation in time to event analysis (adjusted hazard ratio 1.84 [95% confidence interval {CI}, 1.50, 2.26])., Conclusions: Current OAT was associated with a higher likelihood of HCV treatment initiation. However, many PWUD with HCV currently receiving OAT have yet to receive HCV treatment. Enhanced integration between substance use care and HCV treatment is needed to improve the overall health of PWUD., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Importance: Initiation of injection drug use may be more frequent among people dispensed prescription opioid therapy for noncancer pain, potentially increasing the risk of hepatitis C virus (HCV) acquisition., Objective: To assess the association between medically dispensed long-term prescription opioid therapy for noncancer pain and HCV seroconversion among individuals who were initially injection drug use-naive., Design, Setting, and Participants: A population-based, retrospective cohort study of individuals tested for HCV in British Columbia, Canada, with linkage to outpatient pharmacy dispensations, was conducted. Individuals with an initial HCV-negative test result followed by 1 additional test between January 1, 2000, and December 31, 2017, and who had no history of substance use at baseline (first HCV-negative test), were included. Participants were followed up from baseline to the last HCV-negative test or estimated date of seroconversion (midpoint between HCV-positive and the preceding HCV-negative test)., Exposures: Episodes of prescription opioid use for noncancer pain were defined as acute (<90 days) or long-term (≥90 days). Prescription opioid exposure status (long-term vs prescription opioid-naive/acute) was treated as time-varying in survival analyses. In secondary analyses, long-term exposure was stratified by intensity of use (chronic vs. episodic) and by average daily dose in morphine equivalents (MEQ)., Main Outcomes and Measures: Multivariable Cox regression models were used to assess the association between time-varying prescription opioid status and HCV seroconversion., Results: A total of 382 478 individuals who had more than 1 HCV test were included, of whom more than half were female (224 373 [58.7%]), born before 1974 (201 944 [52.8%]), and younger than 35 years at baseline (196 298 [53.9%]). Participants were followed up for 2 057 668 person-years and 1947 HCV seroconversions occurred. Of the participants, 41 755 people (10.9%) were exposed to long-term prescription opioid therapy at baseline or during follow-up. The HCV seroconversion rate per 1000 person-years was 0.8 among the individuals who were prescription opioid-naive/acute (1489 of 1947 [76.5%] seroconversions; 0.4% seroconverted within 5 years) and 2.1 with long-term prescription opioid therapy (458 of 1947 [23.5%] seroconversions; 1.1% seroconverted within 5 years). In multivariable analysis, exposure to long-term prescription opioid therapy was associated with a 3.2-fold (95% CI, 2.9-3.6) higher risk of HCV seroconversion (vs prescription opioid-naive/acute). In separate Cox models, long-term chronic use was associated with a 4.7-fold higher risk of HCV seroconversion (vs naive/acute use 95% CI, 3.9-5.8), and long-term higher-dose use (≥90 MEQ) was associated with a 5.1-fold higher risk (vs naive/acute use 95% CI, 3.7-7.1)., Conclusions and Relevance: In this cohort study of people with more than 1 HCV test, long-term prescription opioid therapy for noncancer pain was associated with a higher risk of HCV seroconversion among individuals who were injection drug use-naive at baseline or at prescription opioid initiation. These results suggest injection drug use initiation risk is higher among people dispensed long-term therapy and may be useful for informing approaches to identify and prevent HCV infection. These findings should not be used to justify abrupt discontinuation of long-term therapy, which could increase risk of harms.

Objective: To assess the association between long term prescription opioid treatment medically dispensed for non-cancer pain and the initiation of injection drug use (IDU) among individuals without a history of substance use., Design: Retrospective cohort study., Setting: Large administrative data source (containing information for about 1.7 million individuals tested for hepatitis C virus or HIV in British Columbia, Canada) with linkage to administrative health databases, including dispensations from community pharmacies., Participants: Individuals age 11-65 years and without a history of substance use (except alcohol) at baseline., Main Outcome Measures: Episodes of prescription opioid use for non-cancer pain were identified based on drugs dispensed between 2000 and 2015. Episodes were classified by the increasing length and intensity of opioid use (acute (lasting <90 episode days), episodic (lasting ≥90 episode days; with <90 days' drug supply and/or <50% episode intensity), and chronic (lasting ≥90 episode days; with ≥90 days' drug supply and ≥50% episode intensity)). People with a chronic episode were matched 1:1:1:1 on socioeconomic variables to those with episodic or acute episodes and to those who were opioid naive. IDU initiation was identified by a validated administrative algorithm with high specificity. Cox models weighted by inverse probability of treatment weights assessed the association between opioid use category (chronic, episodic, acute, opioid naive) and IDU initiation., Results: 59 804 participants (14 951 people from each opioid use category) were included in the matched cohort, and followed for a median of 5.8 years. 1149 participants initiated IDU. Cumulative probability of IDU initiation at five years was highest for participants with chronic opioid use (4.0%), followed by those with episodic use (1.3%) and acute use (0.7%), and those who were opioid naive (0.4%). In the inverse probability of treatment weighted Cox model, risk of IDU initiation was 8.4 times higher for those with chronic opioid use versus those who were opioid naive (95% confidence interval 6.4 to 10.9). In a sensitivity analysis limited to individuals with a history of chronic pain, cumulative risk for those with chronic use (3.4% within five years) was lower than the primary results, but the relative risk was not (hazard ratio 9.7 (95% confidence interval 6.5 to 14.5)). IDU initiation was more frequent at higher opioid doses and younger ages., Conclusions: The rate of IDU initiation among individuals who received chronic prescription opioid treatment for non-cancer pain was infrequent overall (3-4% within five years) but about eight times higher than among opioid naive individuals. These findings could have implications for strategies to prevent IDU initiation, but should not be used as a reason to support involuntary tapering or discontinuation of long term prescription opioid treatment., Competing Interests: Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest/ and declare: support from British Columbia Centre for Disease Control and the Canadian Institutes of Health Research for the submitted work; outside of the submitted work, MK has received research grant funding via his institution from Roche Molecular Systems, Siemens Healthcare Diagnostics, and Hologic; MEK has received consulting fees from Biogen; and RCD has performed research and consulted on the over-the-counter product Tylenol for the consumer division of Johnson & Johnson. RCD is executive director of the RADARS System, which performs post-marketing surveillance of prescription drugs. This information is primarily used for regulatory purposes. Subscribers to the RADARS System include the US Food and Drug Administration and some manufacturers of prescription analgesics or treatment for opioid addiction. These companies include Collegium, Purdue Pharma, and Indivior. All other authors report no financial relationships with any organisations that might have an interest in the submitted work in the previous three years. All authors report no other relationships or activities that could appear to have influenced the submitted work., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

New forms of HIV pre-exposure prophylaxis (PrEP) include long-acting injectables and topical microbicides, each with unique attributes that may appeal to distinct users. We used a discrete choice experiment to characterize preferences for new PrEP formulations among Toronto men who have sex with men. MSM undergoing anonymous HIV testing completed a discrete choice experiment with 12 choice sets by selecting their preferred option within each set. Each set included "usual methods to prevent HIV" (excluding PrEP) as one alternative and two hypothetical PrEP alternatives, which differed according formulation/dosing, side effects (none/mild), risk of drug resistance (none/low/moderate), and HIV prevention efficacy (50%, 65%, 80% or 99% risk reduction). We used mixed logistic regression to infer preferences for PrEP attributes and calculate the marginal rate of substitution between efficacy and other PrEP attributes. 306 men with median (interquartile range) age = 29 (25, 36) years participated, and reported 6 (3, 10) partners and 0 (0, 2) condomless receptive anal sex acts in the preceding six months. An on-demand pill was the most preferred formulation, followed by a monthly injection, daily pill, and on-demand rectal gel. Drug resistance was an important determinant of preferences if the risk was moderate, but not if it was low. The minimum efficacy required for an on-demand pill to be preferred over no PrEP was 32.6% (95%CI = 21.2-43.9%); for a daily pill, injections, and rectal gel, minimum efficacy was 57.9% (95%CI = 44.1-71.7%), 40.1% (27.0-53.2%), and 71.3% (60.5-82.1%), respectively. Attitudes towards PrEP formulations vary among men who have sex with men, with on-demand pills and monthly injections having the highest average preference scores. Understanding these preferences may help to predict uptake., (© 2021. The Author(s).)

Background & Aims: We evaluated the effect of direct-acting antiviral (DAA)-induced sustained virologic response (SVR) on all-cause, liver- and drug-related mortality in a population-based cohort in British Columbia, Canada., Methods: We used data from the British Columbia Hepatitis Testers Cohort, which includes people tested for HCV since 1990, linked with data on medical visits, hospitalizations, prescription drugs and mortality. We followed people who received DAAs and people who did not receive any HCV treatment to death or December 31, 2019. We used inverse probability of treatment weighting to balance the baseline profile of treated and untreated individuals and performed multivariable proportional hazard modelling to assess the effect of DAAs on mortality., Results: Our cohort comprised 10,851 people treated with DAAs (SVR 10,426 [96%], no-SVR: 425) and 10,851 matched untreated individuals. Median follow-up time was 2.2 years (IQR 1.3-3.6; maximum 6.2). The all-cause mortality rate was 19.5/1,000 person-years (PY) among the SVR group (deaths = 552), 86.5/1,000 PY among the no-SVR group (deaths = 96), and 99.2/1,000 PY among the untreated group (deaths = 2,133). In the multivariable model, SVR was associated with significant reduction in all-cause (adjusted hazard ratio [aHR] 0.19; 95% CI 0.17-0.21), liver- (adjusted subdistribution HR [asHR] 0.22, 95% CI 0.18-0.27) and drug-related mortality (asHR 0.26, 95% CI 0.21-0.32) compared to no-treatment. Older age and cirrhosis were associated with higher risk of liver-related mortality while younger age, injection drug use (IDU), problematic alcohol use and HIV/HBV co-infections were associated with a higher risk of drug-related mortality., Conclusions: DAA treatment is associated with a substantial reduction in all-cause, liver- and drug-related mortality. The association of IDU and related syndemic factors with a higher risk of drug-related mortality calls for an integrated social support, addiction, and HCV care approach among people who inject drugs., Lay Summary: We assessed the effect of treatment of hepatitis C virus infection with direct-acting antiviral drugs on deaths from all causes, liver disease and drug use. We found that treatment with direct-acting antiviral drugs is associated with substantial lowering in risk of death from all causes, liver disease and drug use among people with hepatitis C virus infection., Competing Interests: Conflict of interest MK has received grant funding via his institution from Roche Molecular Systems, Boehringer Ingelheim, Merck, Siemens Healthcare Diagnostics and Hologic Inc. SB has advised and spoken for Gilead Sciences (all personal payments given as unrestricted donations to BC Centre for Disease Control Foundation for Public Health). Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2021 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

This study identified factors associated with hospital admission among people with laboratory-diagnosed COVID-19 cases in British Columbia. The study used data from the BC COVID-19 Cohort, which integrates data on all COVID-19 cases with data on hospitalizations, medical visits, emergency room visits, prescription drugs, chronic conditions and deaths. The analysis included all laboratory-diagnosed COVID-19 cases in British Columbia to 15 January 2021. We evaluated factors associated with hospital admission using multivariable Poisson regression analysis with robust error variance. Of the 56,874 COVID-19 cases included in the analysis, 2298 were hospitalized. Factors associated with increased hospitalization risk were as follows: male sex (adjusted risk ratio (aRR) = 1.27; 95% CI = 1.17-1.37), older age ( p -trend < 0.0001 across age groups increasing hospitalization risk with increasing age [aRR 30-39 years = 3.06; 95% CI = 2.32-4.03, to aRR 80+ years = 43.68; 95% CI = 33.41-57.10 compared to 20-29 years-old]), asthma (aRR = 1.15; 95% CI = 1.04-1.26), cancer (aRR = 1.19; 95% CI = 1.09-1.29), chronic kidney disease (aRR = 1.32; 95% CI = 1.19-1.47), diabetes (treated without insulin aRR = 1.13; 95% CI = 1.03-1.25, requiring insulin aRR = 5.05; 95% CI = 4.43-5.76), hypertension (aRR = 1.19; 95% CI = 1.08-1.31), injection drug use (aRR = 2.51; 95% CI = 2.14-2.95), intellectual and developmental disabilities (aRR = 1.67; 95% CI = 1.05-2.66), problematic alcohol use (aRR = 1.63; 95% CI = 1.43-1.85), immunosuppression (aRR = 1.29; 95% CI = 1.09-1.53), and schizophrenia and psychotic disorders (aRR = 1.49; 95% CI = 1.23-1.82). In an analysis restricted to women of reproductive age, pregnancy (aRR = 2.69; 95% CI = 1.42-5.07) was associated with increased risk of hospital admission. Older age, male sex, substance use, intellectual and developmental disability, chronic comorbidities, and pregnancy increase the risk of COVID-19-related hospitalization.

Introduction: Increasing evidence indicates that chronic hepatitis C virus (HCV) infection is associated with higher risk of diabetes. Previous studies showed ethnic disparities in the disease burden of diabetes, with increased risk in Asian population. We described the incidence of type 2 diabetes related to HCV infection and assessed the concurrent impact of HCV infection and ethnicity on the risk of diabetes., Research Design and Methods: In British Columbia Hepatitis Testers Cohort, individuals were followed from HCV diagnosis to the earliest of (1) incident type 2 diabetes, (2) death or (3) end of the study (December 31, 2015). Study population included 847 021 people. Diabetes incidence rates in people with and without HCV were computed. Propensity scores (PS) analysis was used to assess the impact of HCV infection on newly acquired diabetes. PS-matched dataset included 117 184 people. We used Fine and Gray multivariable subdistributional hazards models to assess the effect of HCV and ethnicity on diabetes while adjusting for confounders and competing risks., Results: Diabetes incidence rates were higher among people with HCV infection than those without. The highest diabetes incidence rate was in South Asians with HCV (14.7/1000 person-years, 95% CI 12.87 to 16.78). Compared with Others, South Asians with and without HCV and East Asians with HCV had a greater risk of diabetes. In the multivariable stratified analysis, HCV infection was associated with increased diabetes risk in all subgroups: East Asians, adjusted HR (aHR) 3.07 (95% CI 2.43 to 3.88); South Asians, aHR 2.62 (95% CI 2.10 to 3.26); and Others, aHR 2.28 (95% CI 2.15 to 2.42)., Conclusions: In a large population-based linked administrative health data, HCV infection was associated with higher diabetes risk, with a greater relative impact in East Asians. South Asians had the highest risk of diabetes. These findings highlight the need for care and screening for HCV-related chronic diseases such as type 2 diabetes among people affected by HCV., Competing Interests: Competing interests: DJ is supported by the CIHR Frederick Banting and Charles Best Doctoral Award and the Canadian Network on Hepatitis C PhD fellowship. MEK is supported by the Michael Smith Foundation for Health Research Scholar award and holds research grants from the Natural Sciences and Engineering Research Council of Canada and BC SUPPORT Unit. Over the past 3 years, MEK has received consulting fees from Biogen (unrelated to this project). MK has received grant/research support from Roche, Merck, Siemens, Boehringer Ingelheim and Hologic. SW, JW, ZAB, MB, PAA, SB, MP, EC, AY, MA, HS, HAVG, YA and NZJ have no conflicts of interest to declare., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Prescription opioids (POs) are widely prescribed for chronic non-cancer pain but are associated with several risks and limited long-term benefit. Large, linked data sources are needed to monitor their harmful effects. We developed and characterised a retrospective cohort of people dispensed POs., Participants: We used a large linked administrative database to create the Opioid Prescribing Evaluation and Research Activities cohort of individuals dispensed POs for non-cancer pain in British Columbia (BC), Canada (1996-2015). We created definitions to categorise episodes of PO use based on a review of the literature (acute, episodic, chronic), developed an algorithm for inferring clinical indication and assessed patterns of PO use across a range of characteristics., Findings to Date: The current cohort includes 1.1 million individuals and 3.4 million PO episodes (estimated to capture 40%-50% of PO use in BC). The majority of episodes were acute (81%), with most prescribed for dental or surgical pain. Chronic use made up 3% of episodes but 88% of morphine equivalents (MEQ). Across the acute to episodic to chronic episode gradient, there was an increasing prevalence of higher potency POs (hydromorphone, oxycodone, fentanyl, morphine), long-acting formulations and chronic pain related indications (eg, back, neck, joint pain). Average daily dose (MEQ) was similar for acute/episodic but higher for chronic episodes. Approximately 7% of the cohort had a chronic episode and chronic pain was the characteristic most strongly associated with chronic PO use. Individuals initiating a chronic episode were also more likely to have higher social/material deprivation and previous experience with a mental health condition or a problem related to alcohol or opioid use. Overall, these findings suggest our episode definitions have face validity and also provide insight into characteristics of people initiating chronic PO therapy., Future Plans: The cohort will be refreshed every 2 years. Future analyses will explore the association between POs and adverse outcomes., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Pre-exposure prophylaxis (PrEP) is traditionally prescribed by HIV specialist physicians. Given finite specialist resources, there is a need to scale up PrEP delivery by decentralizing services via other healthcare professionals. We aimed to assess the feasibility of delivering PrEP to men who have sex with men (MSM) through primary care physicians and sexual health clinic nurses. We piloted a multi-component, implementation and dissemination research program to increase provision of PrEP through primary care physicians and sexual health clinic nurses in Toronto, Canada. Community-based organizations (CBOs) provided prospective participants with information cards that contained links to an online module on engaging providers in a conversation about PrEP. In our patient-initiated continuing medical education (PICME) strategy, participants saw their family doctors and gave them the card, which also contained a link to a Continuing Medical Education module. In the nurse-led strategy, participants visited one of two participating clinics to obtain PrEP. We administered an optional online questionnaire to patients and providers at baseline and six months. CBOs distributed 3043 cards. At least 339 men accessed the online module and 196 completed baseline questionnaires. Most (55%) intended to visit nurses while 21% intended to consult their physicians. Among 45 men completing follow-up questionnaires at 6 months, 31% reported bringing cards to their physicians and obtaining PrEP through them; sexual health clinics delivered PrEP to 244 patients. Participants who went through the PICME approach reported no changes in relationships with their providers. Nurses showed fidelity to PrEP prescribing guidelines. Nurse-led PrEP and patient-initiated continuing medical education (PICME) for primary care physicians are feasible strategies to increase PrEP uptake. Nurse-led PrEP delivery was preferred by most patients., Competing Interests: The authors have read the journal’s policy, and the authors of this study have the following competing interests to declare: DHST’s institution has received investigator-driven grants from Gilead Sciences, Abbvie and Viiv Healthcare, and DHST has served as a Site Principal Investigator for clinical trials sponsored by Glaxo Smith Kline, all outside the submitted work. DCK has been a consultant for Merck, Gilead Sciences and Viiv Healthcare, all outside of the submitted work. This does not alter our adherence to PLOS ONE policies on sharing data and materials. There are no patents, products in development or marketed products associated with this research to declare. All other authors have declared that no competing interests exist.

Background & Aims: Hepatitis C virus (HCV) reinfection among high-risk groups threatens HCV elimination goals. We assessed HCV reinfection rates among men who have sex with men (MSM) in British Columbia (BC), Canada., Methods: We used data from the BC Hepatitis Testers Cohort, which includes nearly 1.7 million individuals tested for HCV or HIV in BC. MSM who had either achieved sustained virologic response (SVR) after successful HCV treatment, or spontaneous clearance (SC) and had ≥1 subsequent HCV RNA measurement, were followed from the date of SVR or SC until the earliest of reinfection, death, or last HCV RNA measurement. Predictors of reinfection were identified by Cox proportional modelling. The earliest study start date was 6 November 1997 and latest end date was 13 April 2018., Results: Of 1349 HCV-positive MSM who met the inclusion criteria, 493 had SC while 856 achieved SVR. 349 (25.65%) had HIV coinfection. We identified 98 reinfections during 5203 person-years (PYs) yielding a reinfection rate of 1.88/100PYs. The reinfection rate among SC (2.74/100PYs) was more than twice that of those with SVR (1.03/100 PYs). Problematic alcohol use (aHR 1.73, 95% CI 1.003-2.92), injection drug use (aHR 2.60, 95% CI 1.57-4.29) and HIV coinfection (aHR 2.04, 95% CI 1.29-3.23) were associated with increased risk of HCV reinfection. Mental health counselling history (aHR 0.24, 95% CI 0.13-0.46) was associated with reduced HCV reinfection risk., Conclusions: There is the need to engage MSM in harm reduction and prevention services following treatment to reduce reinfection risk., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: HIV pre-exposure prophylaxis (PrEP) is a proven tool for HIV prevention, but PrEP use in Ontario, Canada, and the effects of recent policies are unknown. We estimated the number and characteristics of PrEP users in Ontario and evaluated the impacts of policy changes between July 2015 and June 2018., Methods: We obtained tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) dispensation data for Ontario from IQVIA, and applied an algorithm to identify use for PrEP. We report prevalent PrEP use for the second quarter of 2018 according to age, sex, region, prescriber specialty, and payer type, and generate "PrEP-to-need ratios" (PNR) by dividing these numbers by the estimated numbers of new HIV diagnoses. We used interventional autoregressive integrated moving average models to examine the impact of three policy changes on PrEP use: Health Canada approval (February 2016), availability of generic TDF/FTC and partial public drug coverage (September 2017), and public drug coverage for individuals aged < 25 years (January 2018)., Results: The estimated number of individuals receiving PrEP increased 713%, from 374 in 2015 Q3 to 3041 in 2018 Q2. Among PrEP users in 2018 Q2, 97.5% were male, 60.4% were < 40 years, 67.7% obtained PrEP from a family physician, 77.2% used private insurance, and 67.0% were in Toronto. PNRs were highest in 30-39-year-olds, males, Toronto and the Central East and West regions. Time series analyses found that Health Canada approval (p = 0.0001) and introducing generics/partial public drug coverage (p = 0.002) led to significantly increased use., Conclusions: PrEP use has risen in Ontario in association with favourable policy changes, but remains far below guideline recommendations.

Objective: Current guidelines in British Columbia recommend prenatal screening for hepatitis C antibodies (anti-HCV) if risk factors are present. We aimed to estimate frequency of prenatal anti-HCV testing, new diagnoses, repeated and follow-up testing among BC women., Methods: BC Centre for Disease Control Public Health Laboratory data estimated the number of BC women (assigned female at birth or unknown sex) aged 13-49 who received routine prenatal serological screening (HIV, hepatitis B, syphilis and rubella) from 2008-2019. Anti-HCV tests ordered the same day as routine prenatal screens were considered prenatal anti-HCV tests. Assessment of follow-up was based on HCV RNA and/or genotype testing within one year of new prenatal anti-HCV diagnoses., Results: In 2019, 55,202 routine prenatal screens were carried out for 50,392 BC women. Prenatal anti-HCV tests increased significantly, from 19.6% (9,704/49,515) in 2008 to 54.6% (27,516/50,392) in 2019 (p<0.001). New prenatal anti-HCV diagnoses (HCV positive diagnoses at first test or seroconversions) declined from 14.3% in 2008 to 10.1% in 2019. The proportion of women with new prenatal anti-HCV diagnoses that were a result of a first HCV test declined from 0.3% (29/9,701) in 2008 to 0.03% (8/27,500) in 2019. For women known to be anti-HCV positive at the time of prenatal screening, the proportion who had a prenatal anti-HCV test increased from 35.6% in 2008 to 50.8% in 2019., Conclusion: Prenatal anti-HCV testing increased substantially over the study period. However, new HCV diagnoses remained relatively stable, suggesting that a considerable proportion of BC women with low or no risk are being screened as part of prenatal care. The vast majority of women with new HCV diagnoses receive appropriate follow-up HCV RNA and genotype testing, which may indicate interest in HCV treatment. These findings contribute to the discussion around potential for prenatal anti-HCV screening in an effort to eliminate HCV., Competing Interests: Dr. Bartlett has received speakers’ honoraria and participated in medical advisory board programs with Gilead Science (all personal payments given as unrestricted donation to BCCDC Foundation).

Background: Patients with chronic kidney disease (CKD) and heart disease face challenging treatment decisions. We sought to explore the perceptions of patients and physicians about shared decision-making for coronary procedures for people with CKD, as well as opinions about strategies and tools to improve these decisions., Methods: We partnered with 4 patients with CKD and 1 caregiver to design and conduct a qualitative descriptive study using semi-structured interviews and content analysis. Patient participants with CKD and either acute coronary syndrome or cardiac catheterization in the preceding year were recruited from a provincial cardiac registry, cardiology wards and clinics in Calgary between March and September 2018. Cardiologists from the region also participated in the study. Data analysis emphasized identifying, organizing and describing themes found within the data., Results: Twenty patients with CKD and 10 cardiologists identified several complexities related to bidirectional information exchange needed for shared decision-making. Themes identified by both patients and physicians included challenges synthesizing best evidence, variable patient knowledge seeking, timeliness in the acute care setting and influence of roles on decision-making. Themes identified by physicians related to processes and tools to help support shared decision-making in this setting included personalization to reflect the variability of risks and heterogeneity of patient preferences as well as allowing for physicians to share their clinical judgment., Interpretation: There are complexities related to bidirectional information exchange between patients with CKD and their physicians for shared decision-making about coronary procedures. Processes and tools to facilitate shared decision-making in this setting require personalization and need to be time sensitive., Competing Interests: Competing interests: Matthew James has received investigator-initiated research grant funding for unrelated work from Amgen Canada. No other competing interests were declared., (Copyright 2020, Joule Inc. or its licensors.)

Background: Hepatitis C (HCV) affects diverse populations such as people who inject drugs (PWID), 'baby boomers,' gay/bisexual men who have sex with men (gbMSM), and people from HCV endemic regions. Assessing HCV syndemics (i.e.relationships with mental health/chronic diseases) among subpopulations using Latent Class Analysis (LCA) may facilitate targeted program planning., Methods: The BC Hepatitis Testers Cohort(BC-HTC) includes all HCV cases identified in BC between 1990 and 2015, integrated with medical administrative data. LCA grouped all BC-HTC HCV diagnosed people(n = 73,665) by socio-demographic/clinical indicators previously determined to be relevant for HCV outcomes. The final model was chosen based on fit statistics, epidemiological meaningfulness, and posterior probability. Classes were named by most defining characteristics., Results: The six-class model was the best fit and had the following names and characteristics: 'Younger PWID'(n =11,563): recent IDU (67%), people born >1974 (48%), mental illness (62%), material deprivation (59%). 'Older PWID'(n =15,266): past IDU (78%), HIV (17%), HBV (17%) coinfections, alcohol misuse(68%). 'Other Middle-Aged People'(n = 9019): gbMSM (26%), material privilege (31%), people born between 1965-1974 (47%). 'People of Asian backgrounds' (n = 4718): East/South Asians (92%), no alcohol misuse (97%) or mental illness (93%), people born <1945 (26%), social privilege (66%). 'Rural baby boomers' (n = 20,401): rural dwellers (32%), baby boomers (79%), heterosexuals (99%), no HIV (100%). 'Urban socially deprived baby boomers' (n = 12,698): urban dwellers (99%), no IDU (100%), liver disease (22%), social deprivation (94%)., Conclusions: Differences between classes suggest variability in patients' service needs. Further analysis of health service utilization patterns may inform optimal service layout., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: The majority of new HCV infections in Canada occur in people who inject drugs. Thus, while curative direct antiviral agents (DAAs) herald a promising new era in hepatitis C virus (HCV) treatment, improving the lives and wellbeing of people living with HCV (PLHCV) must be considered in the context of reducing overdose-related harms and with a syndemic lens. We measure drug-related deaths (DRDs) among HCV-negative people and PLHCV in British Columbia (BC), Canada, and the impact of potent contaminants like fentanyl on deaths., Methods: We identified DRDs among PLHCV and HCV-negative individuals from 2010 to 2018 in the BC Hepatitis Testers Cohort, a population-based dataset of ~1.7 million British Columbians comprising comprehensive administrative and clinical data. We estimated annual standardized liver- and drug-related mortality rates per 100,000 person-years (PY) and described the contribution of specific drugs, including fentanyl and its analogues, implicated in DRDs over time., Results: DRDs constituted 20.1% of deaths among PLHCV and 4.7% of deaths among HCV-negative individuals; a 4.3-fold (95% confidence interval: 4.0-4.5) difference. Drug-related mortality overtook liver-related mortality for PLHCV in 2015 and HCV-negative individuals in 2016 and rose from 241.7 to 436.5 per 100,000 PY from 2010 to 2018 amongPLHCV and from 20.0 to 57.1 per 100,000 PY for HCV-negative individuals over the same period. The proportion of deaths attributable to drugs among PLHCV and HCV-negative individuals increased from 15.1% to 26.1% and 3.1% to 8.0%, in 2010 and 2018, respectively. The proportion of DRDs attributed solely to synthetic opioids such as fentanyl averaged across both groups increased from 2.1% in 2010 to 69.6% in 2017., Conclusion: Steep drug-related mortality increases among PLHCV and HCV-negative individuals over the last decade highlight the urgent need to address overdose-related drivers and harms in these populations using an integrated care approach., Competing Interests: Declarations of Interests MK has received research grant funding via his institution from Roche Molecular Systems, Boehringer Ingelheim, Merck, Siemens Healthcare Diagnostics and Hologic Inc. SRB has received speakers’ honoraria and participated in a medical advisory board program with Gilead Sciences (personal payments given as unrestricted donation to BCCDC Foundation). All other co-authors have no potential conflict of interest to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: In studies showing associations between ambient air pollution and myocardial infarction (MI), data have been lacking on the inherent spatial variability of air pollution. The aim of this study was to determine whether the long-term spatial distribution of air pollution influences short-term temporal associations between air pollution and admission to hospital for MI., Methods: We identified adults living in Calgary who were admitted to hospital for an MI between 2004 and 2012. We evaluated associations between short-term exposure to air pollution (ozone [O 3 ], nitrogen dioxide [NO 2 ], sulfur dioxide [SO 2 ], carbon monoxide [CO], particulate matter < 10 μm in diameter [PM 10 ] and particulate matter < 2.5 μm in diameter [PM 2.5 ]), and hospital admissions for MI using a time-stratified, case-crossover study design. Air Quality Health Index (AQHI) scores were calculated from a composition of O 3 , NO 2 and PM 2.5 . Conditional logistic regression models were stratified by low, medium and high levels of neighbourhood NO 2 concentrations derived from land use regression models; results of these analyses are presented as odds ratios (ORs) with 95% confidence intervals (CIs)., Results: From 2004 to 2012, 6142 MIs were recorded in Calgary. Individuals living in neighbourhoods with higher long-term air pollution concentrations were more likely to be admitted to hospital for MI after short-term elevations in air pollution (e.g., 5-day average NO 2 : OR 1.20, 95% CI 1.03-1.40, per interquartile range [IQR]) as compared with regions with lower air pollution (e.g., 5-day average NO 2 : OR 0.90, 95% CI 0.78-1.04, per IQR). In high NO 2 tertiles, the AQHI score was associated with MI (e.g., 5-day average OR 1.13, 95% CI 1.02-1.24, per IQR; 3-day average OR 1.13, 95% CI 1.04-1.23, per IQR)., Interpretation: Our results show that the effect of air pollution on hospital admissions for MI was stronger in areas with higher NO 2 concentrations than that in areas with lower NO 2 concentrations. Individuals living in neighbourhoods with higher traffic-related pollution should be advised of the health risks and be attentive to special air quality warnings., Competing Interests: Competing interests: Michael Hill reports personal fees from Sun Pharma; nonfinancial support from Hoffmann–La Roche Canada; grants from Covidien (Medtronic), Boehringer–Ingelheim, Stryker, Medtronic and NoNO; and the patent “Systems and Methods for Assisting in Decision-Making and Triaging for Acute Stroke Patients.” Michael Hill owns stock in Calgary Scientific, a company that focuses on medical imaging software, is a director of the Canadian Neurological Sciences Federation, a not-for-profit group, is a director of Circle NeuroVascular, and has received grant support from Alberta Innovates Health Solutions, Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, and the National Institute of Neurological Disorders and Stroke. Gilaad Kaplan has received honoraria for speaking or consultancy from AbbVie, Janssen, Pfizer and Takeda. He has received research support from Ferring, Janssen, AbbVie, GlaxoSmithKline, Merck and Shire. He has been a consultant for Gilead. He shares ownership of a patent: Treatment of Inflammatory Disorders, Autoimmune Disease, and PBC. UTI Limited Partnership, assignee. Patent WO2019046959A1. PCT/CA2018/051098. 7 Sept. 2018. No other competing interests were declared., (Copyright 2020, Joule Inc. or its licensors.)

Background: Clinical trials show high efficacy of sofosbuvir/velpatasvir (SOF/VEL), but there are limited data from "real-world" settings. We aimed to evaluate SOF/VEL effectiveness for all hepatitis C virus (HCV) genotypes (GTs) in British Columbia (BC), Canada., Methods: We used the BC Hepatitis Testers Cohort, which includes all HCV cases in the province (1990-2015) linked to administrative databases, including prescriptions to end of 2018. We measured sustained virologic response (SVR; negative RNA ≥10 weeks after treatment end) and identified characteristics associated with non-SVR. Conservatively, we excluded individuals with no assessment for SVR if their last RNA test after treatment initiation was negative (but included if positive)., Results: Of 2821 eligible participants, most were infected with GT1 (1076, 38.1%) or GT3 (1072, 38.0%), and a minority (278, 9.9%) were treated with RBV. SVR was 94.6% (2670/2821) overall and 94.5% (1017/1076) for GT1, 96.4% (512/531) for GT2, and 93.7% (1004/1072) for GT3. When disaggregated by GT, treatment regimen, and cirrhosis/treatment experience, SVR was lowest (30/40, 75.0%) among treatment-experienced GT3 individuals treated with RBV. Characteristics associated with non-SVR in multivariable analysis included younger age, RBV addition, and being a person with HIV (PWH) or who injects/injected drugs (PWID). When treatment regimen (±RBV) was removed from multivariable model, treatment experience was associated with non-SVR for GT3. Of 151 non-SVR individuals, 56.3% were nonvirological failures (treatment incomplete/no assessment for SVR) and 43.7% were virological failures (nonresponse/relapse). A disproportionately high percentage of non-SVR among PWID was due to nonvirological failure., Conclusions: SOF/VEL was highly effective in this "real-world" population-based cohort. Additional support is required for PWID/PWH to reach SVR., (© The Author(s) 2020. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Purpose: Population-based cohorts of diagnosed people living with HIV (PLWH) are limited worldwide. In Ontario, linked HIV diagnostic and viral load (VL) test databases are centralised and contain laboratory data commonly used to measure engagement in HIV care. We used these linked databases to create a population-based, retrospective cohort of diagnosed PLWH in Ontario, Canada., Participants: A datamart was created by integrating diagnostic and VL databases and linking records at the individual level. These databases contain information on laboratory test results and sociodemographic/clinical information collected on requisition/surveillance forms. Datamart individuals enter our cohort with the first record of a nominal HIV-positive diagnostic test (1985-2015) or VL test (1996-2015), and remain unless administratively lost to follow-up (LTFU; no VL test for >2 years and no VL test in later years). Non-nominal diagnostic tests are excluded as they lack identifying information to permit linkage to other tests. However, individuals diagnosed non-nominally are included in the cohort with record of a VL test. The LTFU rule is applied to indirectly censor for death/out-migration., Findings to Date: As of the end of 2015, the datamart contained 40 372 HIV-positive diagnostic tests and 23 851 individuals with ≥1 VL test. Almost half (46.3%) of the diagnostic tests were non-nominal and excluded, although this was lower (~15%) in recent years. Overall, 29 587 individuals have entered the cohort-contributing 229 302 person-years of follow-up since 1996. Between 2000 and 2015, the number of diagnosed PLWH (cohort individuals not LTFU) increased from 8859 to 16 110, and the percent who were aged ≥45 years increased from 29.1% to 62.6%. The percent of diagnosed PLWH who were virally suppressed (<200 copies/mL) increased from 40.7% in 2000 to 79.5% in 2015., Future Plans: We plan to conduct further analyses of HIV care engagement and link to administrative databases with information on death, migration, physician billing claims and prescriptions. Linkage to other data sources will address cohort limitations and expand research opportunities., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The HIV cascade is an important framework for assessing systems of care, but population-based assessment is lacking for most jurisdictions worldwide. We measured cascade indicators over time in a population-based cohort of diagnosed people living with HIV (PLWH) in Ontario, Canada., Methods: We created a retrospective cohort of diagnosed PLWH using a centralized laboratory database with HIV diagnostic and viral load (VL) test records linked at the individual-level. Individuals enter the cohort with record of a nominal HIV-positive diagnostic test or VL test, and remain unless administratively lost to follow-up (LTFU, >2 consecutive years with no VL test and no VL test in later years). We calculated the annual percent of diagnosed PLWH (cohort individuals not LTFU) between 2000 and 2015 who were in care (≥1 VL test), on ART (as documented on VL test requisition) or virally suppressed (<200 copies/ml). We also calculated time from diagnosis to linkage to care and viral suppression among individuals newly diagnosed with HIV. Analyses were stratified by sex and age. Upper/lower bounds were calculated using alternative indicator definitions., Results: The number of diagnosed PLWH increased from 8,859 (8,859-11,389) in 2000 to 16,110 (16,110-17,423) in 2015. Over this 16-year period, the percent of diagnosed PLWH who were: in care increased from 81% (63-81%) to 87% (81-87%), on ART increased from 55% (34-60%) to 81% (70-82%) and virally suppressed increased from 41% (23-46%) to 80% (67-81%). Between 2000 and 2014, the percent of newly diagnosed individuals who linked to care within three months of diagnosis or achieved viral suppression within six months of diagnosis increased from 67% to 82% and from 22% to 42%, respectively. Estimates were generally lower for females and younger individuals., Discussion: HIV cascade indicators among diagnosed PLWH in Ontario improved between 2000 and 2015, but gaps still remain-particularly for younger individuals., Competing Interests: The authors have declared that no competing interests exist.

Background: Preexposure prophylaxis is efficacious at preventing HIV infection, but concerns persist about adherence and sexually transmitted infections (STIs). We assessed preexposure prophylaxis acceptability, adherence and clinical outcomes in a pilot demonstration project., Methods: HIV-uninfected adult gay and bisexual men who scored 10 or higher on a validated HIV risk score (HIV Incidence Risk Index for MSM) and reported condomless receptive anal sex were sequentially enrolled into a 1-year open-label single-arm pilot study of daily oral therapy with tenofovir disoproxil fumarate/emtricitabine in Toronto. The primary outcome was acceptability of preexposure prophylaxis. Secondary outcomes were preexposure prophylaxis adherence (4-d recall, pill count and dried blood spot analysis), HIV seroconversion, STIs and adverse events., Results: Of the 86 men screened, 52 were enrolled. Participants were mostly young (median age 33 yr [interquartile range (IQR) 28-37 yr) white (38 [73%]) gay (49 [94%]) men. Preexposure prophylaxis acceptability was high: all participants reported their experience as "good" or "very good." The median adherence rate was high, at 100% (IQR 95%-100%) by self-report and 96.9% (IQR 93.4%-98.4%) by pill count. Dried blood spot analysis suggested that doses were taken 4-7 days/week at 88.7% (173/195) of month 3-12 visits. No cases of HIV seroconversion occurred, but 25 participants (48%) experienced at least 1 bacterial STI, with incidence rates per 100 person-years of 32.8, 32.8, 8.2 and 8.2 for chlamydia, gonorrhea, syphilis and lymphogranuloma venereum, respectively. No adverse events led to discontinuation of prophylaxis, but the estimated glomerular filtration rate declined by 0.22 mL/min per month., Interpretation: Preexposure prophylaxis was associated with high adherence and acceptability and no HIV infections in this study. Frequent STIs and clinically unapparent toxic renal effects reinforce the need for ongoing vigilance., Trial Registration: ClinicalTrials. gov, no. NCT02149888., Competing Interests: Competing interests: In the past 2 years, Darrell Tan’s institution has received research support for investigator-initiated research studies from Gilead Sciences and ViiV Healthcare, and Darrell Tan has been a site principal investigator for clinical trials sponsored by GlaxoSmithKline. Janet Raboud is a coinvestigator on several projects with in-kind contributions or research support from Merck & Co. and Gilead Sciences. No other competing interests were declared., (Copyright 2018, Joule Inc. or its licensors.)

Objectives: Pre-exposure prophylaxis (PrEP) is a highly effective, HIV prevention strategy increasingly being accessed by gay, bisexual, and other men who have sex with men (GBMSM). GBMSM face structural and individual-level barriers accessing PrEP, including awareness and cost. This paper assesses socio-demographic factors associated with awareness, interest, and willingness to pay for PrEP in a sample of Canadian GBMSM., Methods: Data were derived from the 2015 Sex Now survey, a cross-sectional, online survey of GBMSM. Respondents were recruited through social media, sex-seeking "apps," and by word of mouth. We used univariable and multivariable logistic regression models to estimate associations between socio-demographic factors and three primary outcomes., Results: Our sample consisted of 7176 HIV-negative Canadian GBMSM. Of respondents, 54.7% were aware of PrEP, 47.4% were interested in PrEP, and 27.9% of PrEP-interested respondents reported they would pay for PrEP out-of-pocket. Awareness and interest varied between provinces, while GBMSM outside urban areas were less likely to be PrEP aware. Bisexual-identified men, and men over 50, were less likely to be aware and interested in PrEP in multivariable models. Only annual income and educational attainment were associated with willingness to pay for PrEP., Conclusion: This study identifies important disparities in awareness, interest, and willingness to pay for PrEP. Future interventions and educational efforts should target non-gay-identified and older GBMSM, as well as GBMSM outside urban areas. PrEP implementation may risk further perpetuating existing health inequities based on socio-economic status if PrEP continues to be accessed primarily through private insurance or paid for out-of-pocket.

Background: Gay, bisexual and other men who have sex with men (gbMSM) in Canada continue to experience high rates of incident HIV. Pre-exposure prophylaxis (PrEP, the regular use of anti-HIV medication) reduces HIV acquisition and could reduce incidence. However, there are too few physicians with expertise in HIV care to meet the projected demand for PrEP. To meet demand and achieve greater public health impact, PrEP delivery could be 'decentralized' by incorporating it into front-line prevention services provided by family physicians (FPs) and sexual health clinic nurses., Methods: This PrEP decentralization project will use two strategies. The first is an innovative knowledge dissemination approach called 'Patient-Initiated CME' (PICME), which aims to empower individuals to connect their family doctors with online, evidence-based, continuing medical education (CME) on PrEP. After learning about the project through community agencies or social/sexual networking applications, gbMSM interested in PrEP will use a uniquely coded card to access an online information module that includes coaching on how to discuss their HIV risk with their FP. They can provide their physician a link to the accredited CME module using the same card. The second strategy involves a pilot implementation program, in which gbMSM who do not have a FP may bring the card to designated sexual health clinics where trained nurses can deliver PrEP under a medical directive. These approaches will be evaluated through quantitative and qualitative methods, including: questionnaires administered to patients and physicians at baseline and at six months; focus groups with patients, FPs, and sexual health clinic staff; and review of sexual health clinic charts. The primary objective is to quantify the uptake of PrEP achieved using each decentralization strategy. Secondary objectives include a) characterizing barriers and facilitators to PrEP uptake for each strategy, b) assessing fidelity to core components of PrEP delivery within each strategy, c) measuring patient-reported outcomes including satisfaction with clinician-patient relationships, and d) conducting a preliminary costing analysis., Discussion: This study will assess the feasibility of a novel strategy for disseminating knowledge about evidence-based clinical interventions, and inform future strategies for scale-up of an underutilized HIV prevention tool.

Systemic lupus erythematosus, scleroderma, myositis and Sjögren's syndrome are rare, complex, multi-systemic rheumatic diseases associated with significant morbidity and mortality. Thorough assessments of disease activity are required to guide clinical management and assess response to new therapies in clinical trials. This article reviews the commonly used outcome measures to assess this group of diseases and discusses the limitations of their use.

Objectives: Pre-exposure prophylaxis (PrEP) with daily oral tenofovir/emtricitabine dramatically reduces HIV risk in men who have sex with men (MSM). However, uptake is slow worldwide., Methods: We administered anonymous cross-sectional questionnaires to MSM presenting for anonymous HIV testing at a Toronto sexual health clinic at four successive time points during the period 2013-2016. We assessed trends in PrEP awareness, acceptability, and use over time using the Cochran-Armitage Trend Test, and identified barriers to using PrEP by constructing "PrEP cascades" using 2016 data. We assumed that to use PrEP, MSM must (a) be at risk for HIV, (b) be at objectively high risk (HIRI-MSM score ≥ 10), (c) perceive themselves to be at medium-to-high risk, (d) be aware of PrEP, (e) be willing to use PrEP, (f) have a family doctor, (g) be comfortable discussing sexual health with that doctor, and (h) have drug coverage/be willing to pay out of pocket., Results: MSM participants were mostly white (54-59.5%), with median age 31 years (IQR = 26-38). PrEP awareness and use increased significantly over time (both p < 0.0001), reaching 91.3% and 5.0%, respectively, in the most recent wave. Willingness to use PrEP rose to 56.5%, but this increase did not reach statistical significance (p = 0.06). The full cascade, ABCDEFGH, suggested few could readily use PrEP under current conditions (11/400 = 2.8%). The largest barriers, in descending order, were low self-perceived HIV risk, unwillingness to use PrEP, and access to PrEP providers., Conclusion: To maximize its potential public health benefits, PrEP scale-up strategies must address self-perceived HIV risk and increase access to PrEP providers.

Background: To maximize public health impact and cost-effectiveness, HIV pre-exposure prophylaxis (PrEP) must reach individuals at high HIV risk. Referrals for PrEP can be self- or provider-initiated, but there are several challenges to both. We assessed whether HIV risk differed by referral source among gay, bisexual and other men who have sex (gbMSM) screening for an HIV PrEP demonstration project., Methods: PREPARATORY-5 was an open-label PrEP demonstration project enrolling gbMSM at high risk of HIV acquisition in Toronto, Canada. Study eligibility criteria related to high risk was defined as scoring ≥10 on the HIV Incidence Risk Index for MSM (HIRI-MSM) and engaging in at least 1 act of condomless receptive anal sex within the past 6 months. Recruitment was promoted through self-referrals (ads in a sexual networking app and gay newspaper/website) and provider-referrals (10 community-based organizations, CBOs). HIV risk score (HIRI-MSM) and syndemic health burden were measured among gbMSM screened for study participation and compared according to referral source., Results: Between October 16 and December 30, 2014, online ads generated 1518 click-throughs and CBOs referred 115 individuals. Overall, 165 men inquired about the trial, of which 86 underwent screening. The majority of screened men were self-referrals (60.5%), scored ≥10 on HIRI-MSM (96.5%), and reported condomless receptive anal sex in the past 6 months (74.2%). Self- and provider-referrals had similarly high HIV risk profiles, with a median (IQR) HIRI-MSM score of 26.0 (19.0-32.5) and 28.5 (20.0-34.0) (p = 0.3), and 75.0% and 73.5% reporting condomless receptive anal sex (p = 0.9), respectively. The overall burden of syndemic health problems was also high, with approximately one-third overall identified as having depressive symptoms (39.5%), alcohol-related problems (39.5%), multiple drug use (31.4%), or sexual compulsivity (31.4%). There were no significant differences in syndemic health problems by referral source., Conclusions: HIV risk and syndemic burden were high among gbMSM presenting for this PrEP demonstration project regardless of referral source. Self-referral may be a useful and efficient strategy for identifying individuals suitable for PrEP use. Online strategies and CBOs working in gay men's health may play important roles in connecting individuals at high HIV risk to PrEP services., Trial Registration: ClinicalTrials.gov NCT02149888 . Registered May 12th 2014.

Pre-exposure prophylaxis (PrEP) has been shown to reduce the risk of HIV transmission but has the potential to cause harm if not used properly. Pharmacists are well-positioned to foster PrEP's efficacy but little is known whether they would endorse it as an HIV prevention tool. The objective of the study was to determine Canadian HIV pharmacists' support for PrEP and to identify current barriers to promoting PrEP. Canadian pharmacists with experience in HIV care were invited to complete an online survey about their experiences, opinions, and learning needs regarding PrEP from December 2012 to January 2013. Among the 59 surveys received, 48 met criteria for final analysis. Overall, 33 (69%) respondents would provide education positively supporting the use of PrEP and 26 (54%) believed Health Canada should approve PrEP for use in Canada. Familiarity with the concept of PrEP and practice characteristics examined did not appear to be significantly associated with support for PrEP in univariable analyses. The principal barriers to promoting PrEP included inadequate drug coverage and insufficient knowledge to educate others. Many Canadian HIV pharmacists would endorse PrEP for high-risk patients; however, wider dissemination of information and lower drug costs may be needed to make PrEP more widely promoted., (© The Author(s) 2015.)

Introduction: Identifying appropriate pre-exposure prophylaxis (PrEP) candidates is a challenge in planning for the safe and effective roll-out of this strategy. We explored the use of a validated HIV risk screening tool, HIV Incidence Risk Index for Men who have Sex with Men (HIRI-MSM), to identify "optimal" candidates among MSM testing at a busy sexual health clinic's community testing sites in Toronto, Canada., Methods: Between November 2014 and April 2015, we surveyed MSM undergoing anonymous HIV testing at community testing sites in Toronto, Canada, to quantify "optimal" candidates for scaling up PrEP roll-out, defined as being at high objective HIV risk (scoring ≥10 on the HIRI-MSM), perceiving oneself at moderate-to-high HIV risk and being willing to use PrEP. Cascades were constructed to identify barriers to broader PrEP uptake. The association between HIRI-MSM score and both willingness to use PrEP and perceived HIV risk were explored in separate multivariable logistic regression analyses., Results: Of 420 respondents, 64.4% were objectively at high risk, 52.5% were willing to use PrEP and 27.2% perceived themselves at moderate-to-high HIV risk. Only 16.4% were "optimal" candidates. Higher HIRI-MSM scores were positively associated with both willingness to use PrEP (aOR=1.7 per 10 score increase, 95%CI=1.3-2.2) and moderate-to-high perceived HIV risk (aOR=1.7 per 10 score increase, 95%CI=1.2-2.3). The proportion of men who were "optimal" candidates increased to 42.9% when the objective HIV risk cut-off was changed to top quartile of HIRI-MSM scores (≥26). In our full cascade, a very low proportion (5.3%) of MSM surveyed could potentially benefit from PrEP under current conditions. The greatest barrier in the cascade was low perception of HIV risk among high-risk men, but considerable numbers were also lost in downstream cascade steps. Of men at high objective HIV risk, 68.3% did not perceive themselves to be at moderate-to-high HIV risk, 23.6% were unaware of PrEP, 40.1% were not willing to use PrEP, 47.6% lacked a family physician with whom they felt comfortable discussing sexual health, and 31.6% had no means to cover the cost of PrEP., Conclusions: A higher HIRI-MSM cut-off may be helpful for identifying candidates for PrEP scale-up. Improving engagement in the PrEP cascade will require interventions to simultaneously address multiple barriers.

A focused lower extremity neurologic evaluation aids in the diagnosis of lower extremity nerve pathology. Injuries to the peripheral neural infrastructure can result in chronic neuropathic pain and discomfort. The most common etiologies of chronic neuropathic pain are from peripheral distal pathologies. A complete lower extremity neurologic evaluation includes sensory, motor, and deep tendon reflexes. Additional specific attention to the geographic anatomic testing of peripheral sensory and motor nerves is essential in eliciting a correct etiologic diagnosis for peripheral neural pain and dysfunction., (Copyright © 2016 Elsevier Inc. All rights reserved.)