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Objective: To compare patterns in use of different antiemetics during pregnancy in Canada, the United Kingdom, and the United States, between 2002 and 2014. Methods: We constructed population-based cohorts of pregnant women using administrative healthcare data from five Canadian provinces (Alberta, British Columbia, Manitoba, Ontario, and Saskatchewan), the Clinical Practice Research Datalink from the United Kingdom, and the IBM MarketScan Research Databases from the United States. We included pregnancies ending in live births, stillbirth, spontaneous abortion, or induced abortion. We determined maternal use of antiemetics from pharmacy claims in Canada and the United States and from prescriptions in the United Kingdom. Results: The most common outcome of 3 848 734 included pregnancies (started 2002–2014) was live birth (66.7% of all pregnancies) followed by spontaneous abortion (20.2%). Use of antiemetics during pregnancy increased over time in all three countries. Canada had the highest prevalence of use of prescription antiemetics during pregnancy (17.7% of pregnancies overall, 13.2% of pregnancies in 2002, and 18.9% in 2014), followed by the United States (14.0% overall, 8.9% in 2007, and 18.1% in 2014), and the United Kingdom (5.0% overall, 4.2% in 2002, and 6.5% in 2014). Besides use of antiemetic drugs being considerably lower in the United Kingdom, the increase in its use over time was more modest. The most commonly used antiemetic was combination doxylamine/pyridoxine in Canada (95.2% of pregnancies treated with antiemetics), ondansetron in the United States (72.2%), and prochlorperazine in the United Kingdom (63.5%). Conclusions: In this large cohort study, we observed an overall increase in antiemetic use during pregnancy, and patterns of use varied across jurisdictions. Continued monitoring of antiemetic use and further research are warranted to better understand the reasons for differences in use of these medications and to assess their benefit-risk profile in this population. [ABSTRACT FROM AUTHOR]

Background: Older Canadians frequently migrate to warmer destinations for the winter season (snowbirds). Our aim was to examine the prevalence of migration to warmer destinations among Ontarians, and to compare the characteristics and use of health care services of snowbirds to those of older Ontarians who did not migrate for the winter. Methods: We conducted a population-based analysis using health administrative databases from Ontario. We compiled 10 seasonal cohorts (2009/10 to 2018/19) of adults aged 65 or more who filled a travel supply of medications under the Ontario Drug Benefits program (snowbirds) between September and January (snowbird season). We calculated the seasonal prevalence of snowbirds per 100 Ontarians aged 65 or more. We matched each snowbird in the 2018/19 season to 2 nonsnowbirds on age and sex, and compared their characteristics and patterns of use of government-funded health care services. Results: Over the 10-year period, 53 431 to 70 863 Ontarians aged 65 or more were identified as snowbirds (seasonal prevalence 2.6%–3.3%). Compared to nonsnowbirds, snowbirds were more likely to be recent migrants, live in higher-income neighbourhoods, have fewer comorbidities and make more visits to primary care physicians. From January to March 2019, snowbirds accessed government-funded health care services for a median of 0 days (interquartile range [IQR] 0–1 d), compared to 4 days (IQR 2–8 d) among nonsnowbirds. Interpretation: About 3% of older Ontarians migrate to warmer destinations for the winter each season. Since few access health care services in Ontario from January to March, researchers are encouraged to consider the snowbird population and the impact of their absence on evaluations that assume continuous observation. [ABSTRACT FROM AUTHOR]

Background: Trends in off-label postpartum use of domperidone and the impact of safety advisories on its use remain unknown. Our objectives were to describe postpartum use of domperidone in Canada, to evaluate the impact of Health Canada advisories on prescribing patterns, and to describe the association between domperidone use and a composite end point of sudden cardiac death or ventricular tachycardia (VT) among postpartum patients. Methods: We conducted a multidatabase cohort study involving pregnant patients with live births between 2004 and 2017 using administrative health databases from 5 Canadian provinces (British Columbia, Alberta, Saskatchewan, Manitoba and Ontario). We excluded patients with less than 1 year of prepregnancy database history and with approved indications for domperidone. We assessed domperidone use in the 6 months postpartum and the impact of the 2012 and 2015 Health Canada advisories on prescribing via interrupted time series analysis. We estimated crude rates of VT and sudden cardiac death. Results: We included 1 190 987 live births. Mean maternal age was 28.6 (standard error 0.6) years. Domperidone use increased over time, from 7% in 2003–2005 to 12% in 2009–2011, when it plateaued. The 2012 advisory was followed by a drop in use and a reduction in slope, and the 2015 advisory had a more modest impact. Crude analysis suggests that domperidone may be associated with increased VT or sudden cardiac death (0.74 v. 0.37 per 10 000 person-years; difference per 10 000 person-years: 0.37, 95% confidence interval −0.67 to 1.41). Interpretation: Postpartum domperidone use increased between 2004 and 2017, with prescribing attenuated after Health Canada advisories and a very low absolute rate of VT or sudden cardiac death. These findings suggest that Health Canada advisories affected prescribing; any potential increase in VT or sudden cardiac death with use of domperidone is small and could not be confirmed in this large study Study registration: ClinicalTrials.gov, no. NCT04024865 [ABSTRACT FROM AUTHOR]

Background: Ankylosing spondylitis (AS) is a chronic inflammatory arthritis affecting the spine in young adults. It is associated with excess cardiovascular and cerebrovascular morbidity.Objective: To determine whether patients with AS are at increased risk for cardiovascular and cerebrovascular mortality.Design: Population-based retrospective cohort study using administrative health data.Setting: Ontario, Canada.Patients: 21 473 patients with AS aged 15 years or older and 86 606 comparators without AS, matched for age, sex, and location of residence.Measurements: The primary outcome was a composite of cardiovascular and cerebrovascular death. Hazard ratios (HRs) for vascular death were calculated; adjusted for history of cancer, diabetes, dementia, inflammatory bowel disease, hypertension, chronic kidney disease, and peripheral vascular disease; and, among those aged 66 years or older, relevant drug therapies. Independent risk factors for vascular mortality were identified in patients with AS.Results: The mean age of patients with AS was 46 years, and 53% were male. Patients and comparators were followed for 166 920 and 686 461 patient-years, respectively. Adjusted HRs for vascular death in AS were 1.36 (95% CI, 1.13 to 1.65) overall, 1.46 (CI, 1.13 to 1.87) in men, and 1.24 (CI, 0.92 to 1.67) in women. Significant risk factors for vascular death were age; male sex; lower income; dementia; chronic kidney disease; peripheral vascular disease; and, among patients aged 65 years or older, lack of exposure to nonsteroidal anti-inflammatory drugs and statins.Limitation: Diagnosis codes for AS were not validated in Ontario.Conclusion: Ankylosing spondylitis is associated with increased risk for vascular mortality. A comprehensive strategy to screen and treat modifiable vascular risk factors in AS is needed.Primary Funding Source: The Arthritis Program, University Health Network, Toronto; and The Arthritis Society, Canada. [ABSTRACT FROM AUTHOR]

Background: Since 2010, tamper-resistant long-acting oxycodone has been available in both the United States and Canada; however, generic non-tamper-resistant brands of the drug have only been introduced in Canada. We aimed to determine whether the introduction of generic non-tamper-resistant oxycodone in Canada led to increased sales from Canadian pharmacies near the Canada-US border. Methods: We conducted a retrospective analysis of trends in dispensing of long-acting oxycodone from Canadian community pharmacies in geographic areas contiguous with the Canada-US border between Feb. 1, 2012, and Jan. 31, 2014. We reported the monthly dispensing rates of long-acting oxycodone by province and within each region near the Canada-US border. Results: During the study period, 8 507 882 long-acting oxycodone tablets were dispensed by Canadian pharmacies in regions near Canada-US border crossings. After the introduction of generic non-tamper-resistant formulations in December 2012, the dispensing rate declined in the border regions of Ontario, British Columbia and Quebec, and rose slightly in Manitoba (4.4%) and New Brunswick (3.6%). Dispensing rates rose by 45.5% in Alberta and 92.3% in Saskatchewan; however, only 3341 of the tablets dispensed were a generic non-tamper-resistant formulation. An examination of the dispensing patterns in 50 border areas after the marketing of non- tamper-resistant brands in Canada showed no patterns suggestive of trafficking. Interpretation: We found no large increases in the dispensing rates of generic non-tamper-resistant long-acting oxycodone in Canadian pharmacies near Canada-US border crossings such as were seen after the withdrawal of OxyContin in the United States in 2010. Despite our findings, Canadian clinicians and pharmacists should remain cautious in their prescribing and dispensing of non- tamper-resistant formulations of oxycodone because of their high potential for misuse and abuse. [ABSTRACT FROM AUTHOR]

Background: With improved survival among children after transplantation, our understanding of the risk for developing other comorbidities is improving, yet little is known about the long-term risk of cardiovascular events and mortality after solid organ transplantation. Methods: In a cohort study using health administrative data, we compared cardiovascular events in children (n = 615) with liver, lung, kidney, small bowel, or multi-organ transplant at the Hospital for Sick Children, Toronto, Canada, with asthmatic children (n = 481,697) between 1996 and 2014. Outcomes included non-fatal cardiovascular events, cardiovascular death, all-cause mortality, and a composite of non-fatal and fatal cardiovascular events. Time-stratified Cox proportional hazards models were used. Results: Among 615 children, 317 (52%) were recipients of kidneys, 253 (41%) of livers, and the remaining 45 (7%) had lung, small bowel, or multi-organ transplants. Median follow-up was 12.1 [7.2, 16.7] years. Non-fatal incident cardiovascular events were 34 times higher among solid organ transplant recipients than non-transplanted children (incidence rate ratio (IRR) 34.4, 95% CI: 25.5, 46.4). Among transplant recipients, the cumulative incidence of non-fatal and fatal cardiovascular events was 2.3% and 13.0%, 5 and 15 years after transplantation, respectively. Conclusions: Increased rate of cardiovascular events in children after transplantation highlights the need for surveillance during transition into adulthood and beyond. A higher resolution version of the Graphical abstract is available as Supplementary information. [ABSTRACT FROM AUTHOR]

Objective Epidemiologic assessments of sufficiently large populations are required in order to obtain robust estimates of disease prevalence and incidence, particularly when exploring the influence of various factors (age, sex, calendar time). We undertook this study to describe the epidemiology of rheumatoid arthritis (RA) over the past 15 years. Methods We used the Ontario Rheumatoid Arthritis administrative Database (ORAD), a validated population-based research database of all Ontarians with RA. The ORAD records were linked with census data to calculate crude and age and sex-standardized prevalence and incidence rates from 1996 to 2010. Vital statistics were used to estimate annual all-cause mortality during the study period. Results As of 2010, there were 97,499 Ontarians with RA, corresponding to a cumulative prevalence of 0.9%. Age and sex-standardized RA prevalence increased steadily over time from 473 (95% confidence interval [95% CI] 469-478) per 100,000 population (0.49%) in 1996 to 784 (95% CI 779-789) per 100,000 population (0.9%) in 2010. Age and sex-standardized incidence per 100,000 population ranged from 62 (95% CI 60-63) in 1996 to 54 (95% CI 52-55) in 2010. All-cause mortality decreased by a relative 21.4% since 1996. Conclusion Over a 15-year period, we observed an increase in RA prevalence over time. This rise may be attributed to the increasing time to ascertain cases (which may have been latent in the population during earlier years of the study), increasing survival, and/or an increase in the aging background population. Incidence appears to be stable. [ABSTRACT FROM AUTHOR]

Background: Although fluoroquinolones are sometimes associated with mild, transient elevations in aminotransferase levels, serious acute liver injury is uncommon. Regulatory warnings have identified moxifloxacin as presenting a particular risk of hepatotoxicity. Thus, we examined the risk of idiosyncratic acute liver injury associated with the use of moxifloxacin relative to other selected antibiotic agents. Methods: We conducted a population-based, nested, case-control study using health care data from Ontario for the period April 2002 to March 2011. We identified cases as outpatients aged 66 years or older with no history of liver disease, and who were admitted to hospital for acute liver injury within 30 days of receiving a prescription for 1 of 5 broadspectrum antibiotic agents: moxifloxacin, levofloxacin, ciprofloxacin, cefuroxime axetil or clarithromycin. For each case, we selected up to 10 age- and sex-matched controls from among patients who had received a study antibiotic, but who were not admitted to hospital for acute liver injury. We calculated odds ratios (ORs) to determine the association between admission to hospital and previous exposure to an antibiotic agent, using clarithromycin as the reference. Results: A total of 144 patients were admitted to hospital for acute liver injury within 30 days of receiving a prescription for one of the identified drugs. Of these patients, 88 (61.1%) died while in hospital. After multivariable adjustment, use of either moxifloxacin (adjusted OR 2.20, 95% confidence interval [CI] 1.21--3.98) or levofloxacin (adjusted OR 1.85, 95% CI 1.01--3.39) was associated with an increase in risk of acute liver injury relative to the use of clarithromycin. We saw no such risk associated with the use of either ciprofloxacin or cefuroxime axetil. Interpretation: Among older outpatients with no evidence of liver disease, moxifloxacin and levofloxacin were associated with an increased risk of acute liver injury relative to clarithromycin. [ABSTRACT FROM AUTHOR]

Background: A relation between provider volume and outcome of total joint replacement (TJR) has not been demonstrated in Canada. Given the recent increase in TJR, changing patient characteristics and small sizes of previous Ontario studies, we reassessed whether adverse outcomes of TJR are related to hospital and surgeon procedure volumes. Methods: We included all Ontarians aged 20 years and older who underwent a unilateral elective primary total hip replacement (THR) or total knee replacement (TKR) between April 2000 and March 2004. The main data sources were hospital discharge abstracts and physician billings. We defined provider volume as the average annual number of primary and revision procedures performed by hospitals and surgeons during the study period. We assessed the association between procedure volumes and acute length of hospital stay (ALOS) and between volume and rate of surgical complications during the index admission; death within 90 days of operation; readmission for amputation, ftision or excision within 1 year; and revision arthroplasty within 1 year. We adjusted for age, sex, comorbidity, arthritis type, teaching hospital status and discharge disposition. The analyses of hospital volume were adjusted for surgeon volume and vice versa. Results: We included 20 290 patients who received THR and 27 217 who received TKR. Patient age, sex and comorbidity were significant predictors of complications and mortality. There were no associations between provider volume and mortality. Findings for other outcomes were mixed. Surgeon procedure volume was related to rates of revision THR but not to rates of revision TKR. Shorter ALOS was associated with male sex, younger age, fewer comorbidities, discharge to a rehabilitation unit or facility and greater surgeon volume. Conclusion: Patient characteristics were significant predictors of complications, ALOS and mortality after primary TJR. Evidence for a relation between provider volume and outcome was limited and inconsistent. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Though statins are fully reimbursed by the public drug programs for seniors in British Columbia (BC) and Ontario, Canada, population-based rates of statin prescription are markedly higher in Ontario. We aimed to assess whether new statin users in BC and Ontario differ in terms of their risk for future coronary heart disease (CHD) events. Study Design and Setting: We collected information for 1998–2001 on demographics, outpatient prescriptions, physician visits, hospital admissions, and vital status from administrative databases to compare the proportions of new statin users aged 66 years and older who had evidence of an acute coronary syndrome (ACS), chronic CHD, neither ACS nor CHD but diabetes, or none of the above. Results: Approximately 15% and 20% of BC and Ontario seniors, respectively, had filled a statin prescription by 2001. Among new statin users in the two provinces, virtually identical proportions had evidence of ACS (8%), chronic CHD (25%), and diabetes (14%), for an overall proportion of roughly 50% at high risk for CHD events. Conclusion: New statin users in BC and Ontario were at similar risk for future CHD events. Poorer case selection is unlikely to explain the relatively higher rates of statin prescription in Ontario. [Copyright &y& Elsevier]

A research letter to the editor focusing on generic warfarin substitution is presented.

Prescription drug plan managers seek "real-world" evidence regarding the safety and effectiveness of drugs and drug coverage policies. University-based pharmaco-epidemiologists with access to administrative health data can help meet these information needs and, by collaborating with other health plans, exploit variations in plan policy. Canada, with its universal health insurance, public drug benefit plans, and population-based linked health care databases, is an ideal setting for such research. Here we describe our initial experience in collaborating with researchers and drug plan managers in British Columbia and Ontario. [ABSTRACT FROM AUTHOR]

Stresses the need for a new approach to drug evaluation in Canada. Types of clinical studies required to inform rational drug policy; Illustration of the proposed model for optimal drug evaluation in Canada; Significance of the act of writing a prescription.

Objective To assess the feasibility and acceptability of a patient workbook for self-assessing coronary risk. Design Pilot study, with post-study physician and patient interviews. Setting and subjects Twenty southern Ontario family doctors and 40 patients for whom they would have used the workbook under normal practice conditions. Interventions The study involved convening two sequential groups of family physicians: the first (n =10) attended focus group meetings to help develop the workbook (using algorithms from the Framingham Heart Study); the second (n =20) used the workbook in practice with 40 patients. Follow-up interviews were by interviewer-administered questionnaire. Main outcome measures Physicians' and patients' opinions of the workbook's format, content, helpfulness, feasibility, and potential for broad application, as well as patients' perceived 10-year risk of a coronary event measured before and after using the workbook. Results It took an average of 18 minutes of physician time to use the workbook: roughly 7 minutes to introduce it to patients, and about 11 minutes to discuss the results. Assessments of the workbook were generally favourable. Most patients were able to complete it on their own (78%), felt they had learned something (80%) and were willing to recommend it to someone else (98%). Similarly, 19 of 20 physicians found it helpful and would use it in practice with an average of 18% of their patients (range: 1–80%). The workbook helped to correct misperceptions patients had about their personal risk of a coronary event over the next 10 years (pre-workbook (mean (SD) %): 35.2 (16.9) vs. post-workbook: 17.3 (13.5), P < 0.0001; estimate according to algorithm: 10.6 (7.6)). Conclusions Given a simple tool, patients can and will assess their own risk of CHD. Such tools could help inform otherwise healthy individuals that their risk is increased, allowing them to make more informed decisions about their behaviours and treatment. [ABSTRACT FROM AUTHOR]

Background: Clinical practice guidelines recommend early serum electrolyte monitoring when starting antidepressants in older adults due to the increased risk of hyponatremia. It is unclear whether this monitoring improves outcomes. Methods: Population‐based, retrospective cohort study of Ontario adults aged ≥66 years who initiated therapy with a selective serotonin reuptake inhibitor (SSRI) or selective norepinephrine reuptake inhibitor (SNRI) between April 1, 2013, and January 31, 2020. The index date was the date of the first such prescription, and the exposure of interest was serum electrolyte measurement during the subsequent 7 days. The primary outcome was any emergency department or hospital admission with hyponatremia within 8–60 days of antidepressant initiation. Poisson regression models compared individuals who had versus did not have their serum electrolytes tested in the week following SSRI/SNRI initiation, weighting by propensity score‐based overlap weights. Results: Among the 420,085 patients aged ≥66 years initiating treatment with an SSRI/SNRI, 26,808 (6.4%) had serum electrolytes measured in the subsequent 7 days and 6109 (1.5%) subsequently presented to hospital with hyponatremia. The time from drug initiation to hospitalization varied (median 29, interquartile range [IQR] 17–44 days), and the median sodium concentration measured in the community (136, IQR 133–138 mmol/L) was marginally higher than those at the time of hospitalization (132, IQR 130–134 mmol/L). Patients who underwent electrolyte testing in the week following SSRI/SNRI treatment were more likely to attend an emergency department (ED) or hospital with hyponatremia within 8–60 days relative to those who did not (relative risk = 2.31, 95% confidence interval: 2.16–2.46). Conclusions: Testing serum electrolytes in the week after starting an SSRI/SNRI is not associated with a reduced risk of a hospital visit with hyponatremia. These findings do not support current guidelines recommending routine electrolyte monitoring. [ABSTRACT FROM AUTHOR]

Discusses the role of a national approach to informed consent for childhood vaccines in improving the national immunization strategy in Canada. Government funding on vaccines; Survey on the standards of care for childhood vaccines; Importance of development and dissemination of vaccine information sheets.

Background: The drug toxicity crisis continues to accelerate across Canada, with rapid increases in opioid-related harms following the onset of the COVID-19 pandemic. We sought to describe trends in the burden of opioid-related deaths across Canada throughout the pandemic, comparing these trends by province or territory, age, and sex. Methods: We conducted a repeated cross-sectional analysis of accidental opioid-related deaths between Jan. 1, 2019, and Dec. 31, 2021, across 9 Canadian provinces and territories using aggregated national data. Our primary measure was the burden of premature opioid-related death, measured by potential years of life lost. Our secondary measure was the proportion of all deaths attributable to opioids; we used the Cochrane–Armitage test for trend to compare proportions. Results: Between 2019 and 2021, the annual number of opioid-related deaths increased from 3007 to 6222 and years of life lost increased from 126 115 to 256 336 (from 3.5 to 7.0 yr of life lost per 1000 population). In 2021, the highest number of years of life lost was among males (181 525 yr) and people aged 30–39 years (87 045 yr). In 2019, we found that 1.7% of all deaths among those younger than 85 years were related to opioids, rising to 3.2% in 2021. Significant increases in the proportion of deaths related to opioids were observed across all age groups (p < 0.001), representing 29.3% and 29.0% of deaths among people aged 20–29 and 30–39 years in 2021, respectively. Interpretation: Across Canada, the burden of premature opioid-related deaths doubled between 2019 and 2021, representing more than one-quarter of deaths among younger adults. The disproportionate loss of life in this demographic group highlights the critical need for targeted prevention efforts. [ABSTRACT FROM AUTHOR]

Purpose: The COVID-19 pandemic had innumerable impacts on healthcare delivery. In Canada, this included limitations on inpatient capacity, which resulted in an increased focus on outpatient surgery for non-emergent cases such as joint replacements. The objective of this study was to assess whether the pandemic and the shift towards outpatient surgery had an impact on access to joint replacement for marginalized patients. Methods: Data from Ontario's administrative healthcare databases were obtained for all patients undergoing an elective hip or knee replacement between January 1, 2018 and August 31, 2021. All surgeries performed before March 15, 2020 were classified as "pre-COVID," while all procedures performed after that date were classified as "post-COVID." The Ontario Marginalization Index domains were used to analyze proportion of marginalized patients undergoing surgery pre- and post-COVID. Results: A total of 102,743 patients were included—42,812 hip replacements and 59,931 knee replacements. There was a significant shift towards outpatient surgery during the post-COVID period (1.1% of all cases pre-COVID to 13.2% post-COVID, p < 0.001). In the post-COVID cohort, there were significantly fewer patients from some marginalized groups, as well as fewer patients with certain co-morbidities, such as congestive heart failure and chronic obstructive pulmonary disease. Conclusion: The most important finding of this population-level database study is that, compared to before the COVID-19 pandemic, there has been a change in the profile of patients undergoing hip and knee replacements in Ontario, specifically across a range of indicators. Fewer marginalized patients are undergoing joint replacement surgery since the COVID-19 pandemic. Further monitoring of access to joint replacement surgery is required in order to ensure that surgery is provided to those who are most in need. [ABSTRACT FROM AUTHOR]

Oral anticoagulant (OAC)-related adverse events are high post-hospitalization. We planned to develop and validate a prediction model for OAC-related harm within 30 days of hospitalization. We undertook a population-based study of adults aged ≥66 years who were discharged from hospital on an OAC from September 2010 to March 2015 in Ontario, Canada. The primary outcome was a composite of time to first hospitalization or emergency department visit for a hemorrhagic or thromboembolic event, or mortality within 30 days of hospital discharge. Cox proportional hazards regression was used to build the model. We included 120,721 patients of which 5423 experienced the outcome. Most patients were aged ≥75 years (59.5%) and were female (55.6%). Sixty percent of the cohort had a follow-up visit with a healthcare provider within 7 days of discharge. Patients discharged on a direct acting OAC versus warfarin (apixaban: Hazard Ratio [HR] 0.82, 95% confidence interval [CI] 0.71-0.94; dabigatran: HR 0.73, 95% CI 0.63-0.84; rivaroxaban: HR 0.79, 95% CI 0.71-0.88), were prevalent users of the dispensed OAC versus incident users (HR 0.82, 95% CI 0.69-0.96), had a joint replacement in the past 35 days (HR 0.40, 95% CI 0.33-0.50) or major surgery during index hospital stay (HR 0.69, 95% CI 0.60-0.80) had a lower risk for the outcome. The Cox model was stable with acceptable discrimination but poor goodness-of-fit. A model for OAC-related harm in the early post-discharge period was developed. External validation studies are required to understand the model's poor calibration. • Transition from hospital to home is a high-risk period for adverse events. • Predictors of OAC-related adverse events early post-discharge are needed. • Clinical factors are significant in predicting risk for OAC-related harm. • Final cox model was stable with acceptable discrimination but poor goodness-of-fit. • Further studies for external validation of our model are required. [ABSTRACT FROM AUTHOR]

Quantifying the contribution of rheumatoid arthritis to the acquisition of subsequent health care costs is an emerging focus of the rheumatologic community and payers of health care. Our objective was to determine the healthcare costs before and after diagnosis of rheumatoid arthritis (RA) from the public payer's perspective. The study design was a longitudinal observational administrative data-based cohort with RA cases from Ontario Canada (n = 104,933) and two control groups, matched 1:1 on year of cohort entry from 2001 to 2016. The first control group was matched on age, sex and calendar year of cohort entry (diagnosis year for those with RA); the second group added medical history to the match before RA diagnosis year. The main exposure was new onset RA. The secondary exposure was calendar year of RA diagnosis to compare attributable costs over the study observation window. Main outcomes were health care costs in 2015 Canadian dollars, overall and by cost category. We used attribution methods to classify costs into those associated with RA, those associated with comorbidities, and age/sex-related underlying costs. Health care costs associated with RA increased up to the year of diagnosis, where they reached $8,591: $4,142 in RA associated costs; $1,242 in RA comorbidity associated costs; and $3,207 in underlying costs. In the eighth-year post diagnosis, the RA costs declined to $2,567 while the RA comorbidity associated costs remained relatively constant at $1,142, and the underlying age/sex related cost increased to $4,426. RA patients had lower costs when diagnosed in later calendar years. Our results suggest a large proportion of disease related health care costs are a result of costs associated with RA comorbidities, which may appear many years before diagnosis. [ABSTRACT FROM AUTHOR]

Background: Bariatric surgery has been shown to significantly reduce cardiovascular risk factors. However, whether surgery can reduce major adverse cardiovascular events (MACE), especially in patients with established cardiovascular disease, remains poorly understood. The present study aims to determine the association between bariatric surgery and MACE among patients with cardiovascular disease and severe obesity.Methods: This was a propensity score-matched cohort study using province-wide multiple-linked administrative databases in Ontario, Canada. Patients with previous ischemic heart disease or heart failure who received bariatric surgery were matched on age, sex, heart failure history, and a propensity score to similar controls from a primary care medical record database in a 1:1 ratio. The primary outcome was the incidence of extended MACE (first occurrence of all-cause mortality, myocardial infarction, coronary revascularization, cerebrovascular events, and heart failure hospitalization). Secondary outcome included 3-component MACE (myocardial infarction, ischemic stroke, and all-cause mortality). Outcomes were evaluated through a combination of matching via propensity score and subsequent multivariable adjustment.Results: A total of 2638 patients (n=1319 in each group) were included, with a median follow-up time of 4.6 years. The primary outcome occurred in 11.5% (151/1319) of the surgery group and 19.6% (259/1319) of the controls (adjusted hazard ratio [HR], 0.58 [95% CI, 0.48-0.71]; P<0.001). The association was notable for those with heart failure (HR, 0.44 [95% CI, 0.31-0.62]; P<0.001; absolute risk difference, 19.3% [95% CI, 12.0%-26.7%]) and in those with ischemic heart disease (HR, 0.60 [95% CI, 0.48-0.74]; P<0.001; absolute risk difference, 7.5% [95% CI, 4.7%-10.5%]). Surgery was also associated with a lower incidence of the secondary outcome (HR, 0.66 [95% CI, 0.52-0.84]; P=0.001) and cardiovascular mortality (HR, 0.35 [95% CI, 0.15-0.80]; P=0.001).Conclusions: Bariatric surgery was associated with a lower incidence of MACE in patients with cardiovascular disease and obesity. These findings require confirmation by a large-scale randomized trial. [ABSTRACT FROM AUTHOR]

Background: Oral anticoagulants are commonly used high-risk medications, but little is known about their safety in transition from hospital to home. Our objective was to measure the rates of hemorrhage and thromboembolic events among older adults receiving oral anticoagulant treatment early after hospital discharge compared to later. Methods: We conducted a retrospective population-based cohort study among Ontario residents aged 66 years or more who started, continued or resumed oral anticoagulant therapy at hospital discharge between September 2010 and March 2015. We calculated the rates of hemorrhage and thromboembolic events requiring hospital admission or an emergency department visit over a 1-year follow-up period, stratified by the first 30 days after discharge and the remainder of the year. We used multivariable regression models, adjusting for covariates, to estimate the effect of sex, prevalent versus incident use, and switching anticoagulants on events. Results: A total of 123 139 patients (68 408 women [55.6%]; mean age 78.2 yr) were included. About one-quarter (32 563 [26.4%]) had a Charlson Comorbidity Index score of 2 or higher. The rates of hemorrhage and thromboembolic events per 100 person-years were highest during the first 30 days after hospital discharge (25.8, 95% CI 24.8–26.8 and 19.3, 95% CI 18.4–20.2, respectively), falling to 15.7 (95% CI 15.3–16.1) and 6.9 (95% CI 6.6–7.1), respectively, during the subsequent 11 months. Multivariable analysis showed that patients whose anticoagulant was switched in hospital and men had more hemorrhages and thromboembolic events in follow-up. Interpretation: The first few weeks following hospital discharge represent a very high-risk period for adverse events related to oral anticoagulant treatment among older adults. The results support an intervention trial addressing anticoagulation management in the early postdischarge period. [ABSTRACT FROM AUTHOR]

Introduction. Des recherches antérieures ont suggéré que le mode de rémunération des médecins peut avoir une influence sur l’exhaustivité des demandes de remboursement lors de l’estimation des maladies chroniques. Le but de cette étude est d’estimer l’exhaustivité des données sur la facturation des médecins dans l’optique de déterminer des cas de diabète. Méthodologie. Nous avons utilisé les données administratives de huit provinces canadiennes pour la période du 1er avril 2014 au 31 mars 2016. Nous avons divisé la cohorte de patients en deux groupes mutuellement exclusifs en fonction du mode de rémunération de leur médecin : médecins rémunérés à l’acte pour ceux payés uniquement de cette façon et médecins non rémunérés à l’acte pour les autres. À l’aide des données sur les ordonnances de médicaments hypoglycémiants (source de nos données de référence), nous avons évalué si les cas de maladie avaient été déterminés avec la même exactitude en fonction du mode de rémunération. Nous avons ensuite corrigé les taux d’incidence du diabète afin d’optimiser l’exhaustivité des cas déterminés. Résultats. La cohorte comprenait 86 110 patients. Dans l’ensemble, des proportions égales de patients ont reçu leurs médicaments hypoglycémiants de la part de médecins rémunérés à l’acte et de médecins non rémunérés à l’acte. Globalement, le mode de rémunération des médecins a eu peu d’effet sur le pourcentage de cas de diabète omis (14,8 % chez les médecins rémunérés à l’acte contre 12,2 % chez les médecins non rémunérés à l’acte). Toutefois, la différence de cas omis entre les médecins rémunérés à l’acte et ceux non rémunérés à l’acte était très variable d’une province à l’autre, allant de -1,0 % en Nouvelle-Écosse à 29,9 % à Terre-Neuve-et-Labrador. La différence entre les taux observés d’incidence de la maladie et les taux corrigés était également variable d’une province à l’autre, allant de 22 % à l’Île-du-Prince-Édouard à 4 % en Nouvelle-Écosse. Conclusion. La différence entre le nombre de cas omis selon le mode de rémunération des médecins est variable d’une province à l’autre. Cette perte de données contribue probablement à une sous-estimation de l’incidence de la maladie. Il serait possible d’appliquer la méthode que nous avons utilisée à d’autres maladies chroniques pour lesquelles des données de traitement pharmacologique pourraient servir de données de référence. [ABSTRACT FROM AUTHOR]

Background: Virtual urgent care (VUC) is intended to support diversion of patients with low-acuity complaints and reduce the need for in-person emergency department visits. We aimed to describe subsequent health care utilization and outcomes of patients who used VUC compared with similar patients who had an in-person emergency department visit. Methods: We used patient-level encounter data that were prospectively collected for patients using VUC services provided by 14 pilot programs in Ontario, Canada. We linked the data to provincial administrative databases to identify subsequent 30-day health care utilization and outcomes. We defined 2 subgroups of VUC users; those with a documented prompt referral to an emergency department by a VUC provider, and those without. We matched patients in each cohort to an equal number of patients presenting to an emergency department in person, based on encounter date, medical concern and the logit of a propensity score. For the subgroup of patients not promptly referred to an emergency department, we matched patients to those who were seen in an emergency department and then discharged home. Results: Of the 19 595 patient VUC visits linked to administrative data, we matched 2129 patients promptly referred to the emergency department by a VUC provider to patients presenting to the emergency department in person. Index visit hospital admissions (9.4% v. 8.7%), 30-day emergency department visits (17.0% v. 17.5%), and hospital admissions (12.9% v. 11.0%) were similar between the groups. We matched 14 179 patients who were seen by a VUC provider with no documented referral to the emergency department. Patients seen by VUC were more likely to have a subsequent in-person emergency department visit within 72 hours (13.7% v. 7.0%), 7 days (16.5% v. 10.3%) and 30 days (21.9% v. 17.9%), but hospital admissions were similar within 72 hours (1.1% v. 1.3%), and higher within 30 days for patients who were discharged home from the emergency department (2.6% v. 3.4%). Interpretation: The impact of the provincial VUC pilot program on subsequent health care utilization was limited. There is a need to better understand the inherent limitations of virtual care and ensure future virtual providers have timely access to in-person outpatient resources, to prevent subsequent emergency department visits. [ABSTRACT FROM AUTHOR]

Background: Outcomes following total hip arthroplasty (THA) and total knee arthroplasty (TKA) with a short length of hospital stay have been reported; however, most studies have not accounted for an inherent patient selection bias and discharge disposition. The purpose of this study was to utilize a propensity score to match and compare the outcomes of patients undergoing THA or TKA with short and longer lengths of stay with a discharge directly home.Methods: An administrative database from Ontario, Canada, which has a single-payer health-care system, was retrospectively reviewed to identify patients who underwent THA or TKA from 2008 to 2016. Patients were subsequently stratified into 2 groups based on their length of stay: short length of stay (≤2 days; thereafter referred to as short stay) and longer length of stay (>2 days; thereafter referred to as longer stay). Using a propensity score, patients who underwent short-stay THA or TKA were matched to patients who underwent longer-stay THA or TKA. Matching was based on 15 demographic, medical, and surgical factors. Our primary outcomes included postoperative complications, health-care utilization (readmission and emergency department presentation), and health-care costs.Results: Overall, 89,656 TKAs (14,645 short stays and 75,011 longer stays) and 52,610 THAs (9,426 short stays and 43,184 longer stays) were included in this study. Patients who underwent short-stay THA or TKA were significantly more likely (p < 0.05) to be younger, male, healthier, and from a higher socioeconomic status and to have undergone the procedure with a higher-volume surgeon. Over 95% of short-stay cases were successfully matched to longer-stay cases, and we found no significant difference in complications, health-care utilization, and costs between patients on the basis of the length of stay.Conclusions: Patients undergoing short-stay THA or TKA with a discharge home were more likely to be younger, healthy, male patients from a higher socioeconomic status. Higher-volume surgeons are also more likely to perform short-stay THA or TKA. These characteristics confirm the previously held belief that a selection bias exists when comparing cohorts based on time to discharge. When comparing matched cohorts of patients who underwent short-stay and longer-stay THA or TKA, we observed no difference in outcomes, suggesting that a short stay with a discharge home in the appropriately selected patient is safe following THA or TKA.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Accurate coding of diagnoses of SARS-CoV-2 infection in administrative data benefits population-based studies about the epidemiology, treatment and outcomes of COVID-19. We describe the validity of diagnoses of SARS-CoV-2 infection recorded in hospital discharge abstracts, emergency department records and outpatient physician service claims from 3 Canadian provinces. Methods: In this cohort study, population-based inpatient, emergency department and outpatient records were linked to SARS-CoV-2 polymerase chain reaction (PCR; reference standard) test results from British Columbia, Manitoba and Ontario for Apr. 1, 2020, to Mar. 31, 2021. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of diagnoses of SARS-CoV-2 infection were estimated for each quarter in the study period, overall and by province, age group and sex. Results: Our study encompassed more than 13 million SARS-CoV-2 PCR test results. Specificity and NPV of diagnoses of SARS-CoV-2 infection were consistently high (i.e., most estimates were > 95%). Overall sensitivity estimates were 86.2%, 60.4% and 20.3% in the first quarter for inpatient, emergency department and outpatient cohorts, and 66.2%, 47.5% and 25.0% in the last quarter, respectively. For inpatients, overall PPV estimates ranged from 50.0% to 66.4%. For emergency department patients, overall PPV estimates were 76.9% and 68.3% in the first and last quarters, respectively. For outpatients, PPV estimates were 6.8% and 29.1% in the first and last quarters, respectively. Interpretation: We found variations in the validity of diagnoses for SARS-CoV-2 infection recorded in different health care settings, geographic areas and over time. Our multiprovince validation study provides evidence about the potential use of inpatient and emergency department records as an alternative to population-based laboratory data for identification of patients with SARS-CoV-2 infection, but does not support the use of outpatient claims for this purpose. [ABSTRACT FROM AUTHOR]

Background: Oxycodone is increasingly prescribed for postpartum analgesia in lieu of codeine owing to concerns regarding the neonatal safety of codeine during lactation. We examined whether initiation of oxycodone after delivery was associated with an increased risk of persistent opioid use relative to initiation of codeine. Methods: We conducted a population-based cohort study of people who filled a prescription for either codeine or oxycodone within 7 days of discharge from hospital after delivery between Sept. 1, 2012, and June 30, 2020. The primary outcome was persistent opioid use, defined as 1 or more additional prescriptions for an opioid within 90 days of the first postpartum prescription and 1 or more additional prescriptions in the 91 to 365 days thereafter. We used inverse probability of treatment weighting to assess the risk of persistent postpartum opioid use, comparing people who initiated oxycodone with those who initiated codeine. Results: Over the 8-year study period, we identified 70 607 people who filled an opioid prescription within 7 days of discharge from hospital: 21 308 (30.2%) received codeine and 49 299 (69.8%) oxycodone. Compared with people who filled a prescription for codeine, receipt of oxycodone was not associated with persistent opioid use (relative risk [RR] 1.04, 95% confidence interval [CI] 0.91–1.20). We found an association between a prescription for oxycodone and persistent use after vaginal delivery (RR 1.63, 95% CI 1.31–2.03), but not after cesarean delivery (RR 0.85, 95% CI 0.73–1.00). Interpretation: Initiation of oxycodone (v. codeine) was not associated with an increased risk of persistent opioid use, except after vaginal delivery. [ABSTRACT FROM AUTHOR]

Background: In February 2012, a reformulated tamper-deterrent form of long-acting oxycodone, OxyNeo, was introduced in Canada. We investigated the impact of the introduction of OxyNeo on patterns of opioid prescribing. Methods: We conducted population-based, cross-sectional analyses of opioid dispensing in Canada between 2008 and 2016. We estimated monthly community pharmacy dispensing of oral formulations of codeine, morphine, hydromorphone and oxycodone, and a transdermal formulation of fentanyl, and converted quantities to milligrams of morphine equivalents (MMEs) per 1000 population. We used time series analysis to evaluate the effect of the introduction of OxyNeo on these trends. Results: National dispensing of long-acting opioids fell by 14.9% between February 2012 and April 2016, from 36 098 MMEs to 30 716 MMEs per 1000 population (p < 0.01). This effect varied across Canada and was largest in Ontario (reduction of 22.8%) (p = 0.01) and British Columbia (reduction of 30.0%) (p = 0.01). The national rate of oxycodone dispensing fell by 46.4% after the introduction of OxyNeo (p < 0.001); this was partially offset by an increase of 47.8% in hydromorphone dispensing (p < 0.001). Although dispensing of immediate-release opioids was a substantial contributor to overall population opioid exposure across Canada, it was unaffected by the introduction of OxyNeo (p > 0.05 in all provinces). Interpretation: The findings suggest that the introduction of a tamper-deterrent formulation of long-acting oxycodone in Canada, against a background of changing public drug benefits, was associated with sustained changes in selection of long-acting opioids but only small changes in the quantity of long-acting opioids dispensed. This illustrates the limited effect a tamper-deterrent formulation and associated coverage policy can have when other, non-tamper-deterrent alternatives are readily available. [ABSTRACT FROM AUTHOR]

Introduction: The recent publication of a national guideline and quality standards in Canada have provided clinicians with new, evidence-based recommendations on safe, appropriate opioid use. We sought to characterize how well opioid initiation practices aligned with these recommendations before and following their release. Methods: We conducted a population-based study among people initiating opioids prior to the release of national guidelines (April 2015—March 2016; fiscal year [FY] 2015) and in the most recent year available (January—December 2019) in Ontario, Canada. We used linked administrative claims data to ascertain the apparent indication for opioid therapy, and characterized the initial daily dose (milligrams morphine or equivalent; MME) and prescription duration for each indication. Results: In FY2015, 653,885 individuals commenced opioids, compared to 571,652 in 2019. Over time, there were small overall reductions in the prevalence of initial daily doses exceeding 50MME (23.9% vs. 20.1%) and durations exceeding 7 days (17.4% vs. 14.8%); but the magnitude of the reductions varied widely by indication. The prevalence of high dose (>50MME) initial prescriptions reduced significantly across all indications, with the exception of dentist-prescribed opioids (13.6% vs. 12.1% above 50MME). In contrast, there was little change in initial durations exceeding 7 days across most indications, with the exception of some surgical indications (e.g. common excision; 9.3% vs. 6.2%) and among those in palliative care (35.2% vs. 29.2%). Conclusion: Despite some modest reductions in initiation of high dose and long duration prescription opioids between 2015 and 2019, clinical practice is highly variable, with opioid prescribing practices influenced by clinical indication. These findings may help identify medical specialties well-suited to targeted interventions to promote safer opioid prescribing. [ABSTRACT FROM AUTHOR]

Background: Anecdotally there are reports of newly diagnosed SARS-CoV-2 infection shortly after vaccination. This has led some to speculate that vaccination itself might inadvertently increase the short-term risk of COVID potentially due to airborne spread at mass vaccination clinics or relaxation of precautions following vaccination. We explored whether receipt of vaccination was associated with a short-term increase in the risk of being diagnosed with COVID-19 and if differences exist between vaccination settings. Methods: We conducted a cohort study in Ontario, Canada to compare the risk of SARS-CoV-2 infection within 21 days of receiving a first vaccination, according to the setting in which vaccines were administered between March 1, 2021 and May 6, 2021. We used linked population-wide vaccination, laboratory testing, and health administrative databases. We created a 1:1 matched comparison group of unexposed individuals. We reported the overall risk of infection calculated at 3, 7, 10, 14, 18, and 21 days. This was completed overall and by setting of vaccine receipt. Results: We identified 4,798,430 Ontario residents who received their first dose of a COVID-19 vaccine. In the primary analysis, the rate of SARS-CoV-2 infection was significantly lower among vaccine recipients vs non-recipients at all the post-vaccination time points. Analysis stratified by vaccination setting found that mass vaccination clinics, pharmacies, and physician offices were consistent with the main findings. Individuals who received their first vaccine dose in congregate residential settings had a higher rate of SARS-CoV-2 infection at 7 days (HR 1.35, 95% CI 1.00–1.83) and 10 days (HR 1.49, 95% CI 1.03–2.15). Conclusion: In this population-based cohort study, we found that there was no increased risk of SARS-CoV2 infection after vaccination suggesting no broad transmission of disease at time of vaccination. Some evidence of increased risk among those vaccinated in congregate settings, highlighting the need to consider opportunities for supporting safe vaccine administration in these settings. Given ongoing and future immunization programs, the results support the need for continued vigilance during any mass vaccination processes and education regarding the delayed nature of protection following vaccination. [ABSTRACT FROM AUTHOR]

Aims: To characterize comparative risks and benefits of methadone versus buprenorphine/naloxone in a contemporary cohort where the unregulated drug supply is dominated by fentanyl. Design, Setting and Participants: Population‐based propensity‐score matched cohort study conducted in Ontario, Canada among people aged 18+ initiating opioid agonist therapy (OAT) for an opioid use disorder between October 2016 and December 2018 (n = 18 880). Intervention: Initiation of methadone versus buprenorphine/naloxone. Measurements The primary outcome was opioid overdose (fatal and non‐fatal) while on treatment, with secondary outcomes including opioid overdose (first 30 days of treatment), treatment discontinuation, health‐care interactions related to treatment of opioid use disorder, receiving a weekly supply of take‐home doses and opioid overdose within 30 days of treatment discontinuation. Outcomes were assessed over 1 year. Findings Overall, 7517 people initiating buprenorphine were matched to an equal number of methadone‐treated individuals. Risk of opioid overdose while on treatment [hazard ratio (HR) = 0.50; 95% confidence interval (CI) = 0.37–0.68] or within the first 30 days of treatment (HR = 0.51, 95% CI = 0.31–0.85) was lower among buprenorphine recipients compared to methadone recipients. In secondary analyses, people initiating buprenorphine had a higher risk of treatment discontinuation within the first year (median time to discontinuation 104 versus 265 days, HR = 1.43, 95% CI = 1.37–1.49), had lower rates of health‐care interactions for OUD (186.4 versus 254.3 per person‐year; rate ratio = 0.73; 95% CI = 0.72–0.75), and a higher rate of receiving weekly take‐home doses (HR = 2.33; 95% CI = 2.20–2.46). Overdose rates in the period following OAT discontinuation were higher than those observed while on treatment, but did not differ significantly by OAT type. Conclusions: Although treatment retention is higher among methadone recipients, overdose risk is also elevated compared to buprenorphine recipients. These findings demonstrate the benefits of any OAT on avoidance of overdose, particularly following treatment discontinuation and with the increasingly unpredictable drug supply in North America. [ABSTRACT FROM AUTHOR]

Background: There are limited published data on population estimates of survival after spinal surgery for metastatic disease. We performed a population-based study to evaluate survival and complications among patients with cancer who underwent surgery for spinal metastases in Ontario, Canada, between 2006 and 2016.Methods: We used health administrative databases to identify all patients who underwent surgery for spinal metastases in Ontario between Jan. 1, 2006, and Dec. 31, 2016. We assessed overall survival, mortality rates according to primary cancer lesion and complications after surgery. We contrast the results to those for a comparable cohort from 1991 to 1998.Results: A total of 2646 patients (1194 women [45.1%]; mean age 62.5 yr [standard deviation 12.2 yr]) were identified. The median survival time was 236 (interquartile range 84-740) days. Mortality was highest for patients with melanoma, upper gastrointestinal cancer and lung cancer, with 50% dying within 90 days of surgery. The longest median survival times were observed for primary cancers of the thyroid (906 d) and breast (644 d), and myeloma (830 d). Overall 90-day and 1-year mortality rates were 29% and 59%, respectively.Conclusion: We identified differential survivorship based on primary tumour type and a shift in the distribution of operations performed for specific primary cancers over the past 2 decades in Ontario. Overall reductions in mortality associated with this shift in treatment may reflect the use of adjuvant therapies and more personalized treatment approaches. [ABSTRACT FROM AUTHOR]

Background: The aims of operative treatment of displaced tibial plateau fractures are to stabilize the injured knee to restore optimal function and to minimize the risk of posttraumatic arthritis and the eventual need for total knee arthroplasty. The purpose of our study was to define the rate of subsequent total knee arthroplasty after tibial plateau fractures in a large cohort and to compare that rate with the rate in the general population. Methods: All patients sixteen years of age or older who had undergone surgical treatment of a tibial plateau fracture from 1996 to 2009 in the province of Ontario, Canada, were identified from administrative health databases with use of surgeon fee codes. Each member of the tibial plateau fracture cohort was matched to four individuals from the general population according to age, sex, income, and urban/rural residence. The rates of total knee arthroplasty at two, five, and ten years were compared by using time-to-event analysis. A separate Cox proportional hazards model was used to explore the influence of patient, provider, and surgical factors on the time to total knee arthroplasty. Results: We identified 8426 patients (48.5% female; median age, 48.9 years) who had undergone fixation of a tibial plateau fracture and matched them to 33,698 controls. The two, five, and ten-year rates of total knee arthroplasty in the plateau fracture and control cohorts were 0.32% versus 0.29%, 5.3% versus 0.82%, and 7.3% versus 1.8%, respectively (p < 0.0001). After adjustment for comorbidity, plateau fracture surgery was found to significantly increase the likelihood of total knee arthroplasty (hazard ratio [HR], 5.29 [95% confidence interval, 4.58, 6.11]; p < 0.0001). Higher rates of total knee arthroplasty were also associated with increasing age (HR, 1.03 [1.03, 1.04] per year over the age of forty-eight; p < 0.0001), bicondylar fracture (HR, 1.53 [1.26, 1.84]; p < 0.0001), and greater comorbidity (HR, 2.17 [1.70, 2.77]; p < 0.001). Conclusions: Ten years after tibial plateau fracture surgery, 7.3% of the patients had had a total knee arthroplasty. This corresponds to a 5.3 times increase in likelihood compared with a matched group from the general population. Older patients and those with more severe fractures are also more likely to need total knee arthroplasty after repair of a tibial plateau fracture. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Abstract: Reports have emerged of abrupt tapering among recipients of long-term prescription opioids to conform new prescribing guidelines. We conducted a population-based, repeated cross-sectional time-series study among very high-dose (≥200 MME) opioid recipients in Ontario, Canada, to examine changes in the monthly prevalence of rapid tapering from 2014 to 2018, defined as recipients experiencing either a ≥50% reduction in daily doses or abrupt discontinuation sustained for 30 days. Interventional autoregressive integrated moving average models were used to test for significant changes following key guidelines and drug policies and programs. A sensitivity analysis examined rapid tapering sustained for 90 days. The monthly prevalence of rapid tapering events was stable from January 2014 to September 2016 (average monthly prevalence: 1.4%) but increased from 1.4% in October 2016 to 1.8% in April 2017 (P = 0.001), coincident with Ontario's Fentanyl Patch-for-Patch Return Program implementation. Transient spikes in the prevalence of rapid tapering also occurred 2 months after Ontario's delisting of publicly funded high-strength opioids and the release of updated Canadian Opioid Prescribing Guideline for Chronic Pain, reaching 2.3% in March 2017 and July 2017, respectively. However, this prevalence decreased to 1.2% in December 2018 (P < 0.0001). Although the prevalence of abrupt opioid discontinuation was lower, similar trends were observed. Our sensitivity analysis examining long-lasting rapid tapering found similar trends but lower prevalence, with no changes in complete discontinuation. These temporary increases in rapid tapering events highlight the need for improved communication and evidence-based resources for prescribers to minimize negative consequences of evolving policies and guidelines. [ABSTRACT FROM AUTHOR]

Objective: To assess whether stroke rates among patients with retinal disease were influenced by the rapid and sequential uptakes of bevacizumab and ranibizumab for age-related macular degeneration (AMD). Design: Population-based, time series analysis using encrypted, linked healthcare databases in Ontario, Canada. Participants: We included all patients aged 66 years or older with physician-diagnosed retinal disease in the previous 5 years between 2002 and 2010 (N = 116 388). A secondary analysis evaluated patients who had undergone photodynamic therapy (PDT) within the preceding year (N = 10 059). Methods: We used segmented regression analysis to evaluate changes in the rate of hospitalization for ischemic stroke associated with the introduction of bevacizumab and ranibizumab. The stroke rate was compared across 3 mutually exclusive periods: the period before the availability of bevacizumab or ranibizumab, the period of bevacizumab dominant AMD therapy, and the period of ranibizumab dominant AMD therapy. Main Outcome Measures: Hospitalizations for ischemic stroke. Results: Among patients with retinal disease, neither the trend nor the level of the stroke time series changed with the uptake of bevacizumab (trend change coefficient −0.0026 stroke hospitalizations/1000 subjects/month [95% confidence interval {CI}, −0.0066 to 0.0014; P = 0.20]; level change coefficient, 0.036 stroke hospitalizations/1000 subjects [95% CI, −0.070 to 0.14; P = 0.51]), or ranibizumab (trend change coefficient: −0.0011 stroke hospitalizations/1000 subjects/month [95% CI, −0.0087 to 0.0065; P = 0.78]; level change coefficient: −0.017 stroke hospitalizations/1000 subjects [95% CI, −0.14 to 0.11; P = 0.79]). Similar results were observed in the analysis restricted to patients with recent PDT and in analyses stratified on age, sex, history of stroke, and history of diabetes. Conclusions: The rapid uptake of vascular endothelial growth factor (VEGF) inhibitors for AMD was not associated with a change in the rate of hospitalization for stroke among Ontario seniors with retinal disease. Furthermore, stroke rates in the bevacizumab and ranibizumab periods were not different. These population-level results complement the findings of a recently published trial comparing bevacizumab and ranibizumab, and may assist clinicians and policy makers as they balance the comparative efficacy, safety, and cost of these 2 closely related treatments. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. [Copyright &y& Elsevier]

Background: Several Canadian provinces have introduced reimbursement policies mandating substitution of innovator biologics with lower-cost biosimilars. We estimated the number of patients affected and cost implications if such policy changes were to be implemented in Ontario, Canada. Methods: We conducted a cross-sectional time series analysis of Ontarians dispensed publicly funded biologics indicated for inflammatory diseases (rheumatic conditions, inflammatory bowel disease: infliximab, etanercept, adalimumab) between January 2018 and December 2019, and forecasted trends to Dec. 31, 2020. The primary source of data was pharmacy claims data for all biologics reimbursed by the public drug program. We modelled the number of patients affected and government expenditures (in nominal Canadian dollars) of several biosimilar policy options, including mandatory nonmedical biosimilar substitution, substitution in new users, introduction of a biosimilar for adalimumab, and price negotiations. In a secondary analysis, we included insulin glargine. Results: In 2018, 14 089 individuals were prescribed a publicly funded biologic for inflammatory diseases. A mandatory nonmedical biosimilar substitution would potentially have affected 7209 patients and saved $238.6 million from 2018 to 2020. A new-user substitution would have affected 757 patients and saved $34.2 million. If an adalimumab biosimilar were to become available, 12 928 patients would be affected by a mandatory nonmedical substitution and the 3-year savings would increase to $645.9 million (all biosimilars priced at 25% of innovator biologics). Finally, an expanded nonmedical substitution policy including insulin glargine would affect 115 895 patients and save $288.7 million (not including adalimumab). Interpretation: Policies designed to curb rising costs of biologics can have substantially different effects on patients and government expenditures. Such analyses warrant careful consideration of the balance between cost savings and effects on patients. [ABSTRACT FROM AUTHOR]

Background: Health care funding reforms are being used worldwide to improve system performance but may invoke unintended consequences. We assessed the effects of introducing a targeted hospital funding model, based on fixed price and volume, for hip fractures. We hypothesized the policy change was associated with reduction in wait times for hip fracture surgery, increase in wait times for non-hip fracture surgery, and increase in the incidence of after-hours hip fracture surgery.Methods: This was a population-based, interrupted time series analysis of 49,097 surgeries for hip fractures, 10,474 for ankle fractures, 1,594 for tibial plateau fractures, and 40,898 for appendectomy at all hospitals in Ontario, Canada between April 2012 and March 2017. We used segmented regression analysis of interrupted monthly time series data to evaluate the impact of funding reform enacted April 1, 2014 on wait time for hip fracture repair (from hospital presentation to surgery) and after-hours provision of surgery (occurring between 1700 and 0700 h). To assess potential adverse consequences of the reform, we also evaluated two control procedures, ankle and tibial plateau fracture surgery. Appendectomy served as a non-orthopedic tracer for assessment of secular trends.Results: The difference (95 % confidence interval) between the actual mean wait time and the predicted rate had the policy change not occurred was - 0.46 h (-3.94 h, 3.03 h) for hip fractures, 1.46 h (-3.58 h, 6.50 h) for ankle fractures, -3.22 h (-39.39 h, 32.95 h) for tibial plateau fractures, and 0.33 h (-0.57 h, 1.24 h) for appendectomy (Figure 1; Table 3). The difference (95 % confidence interval) between the actual and predicted percentage of surgeries performed after-hours - 0.90 % (-3.91 %, 2.11 %) for hip fractures, -3.54 % (-11.25 %, 4.16 %) for ankle fractures, 7.09 % (-7.97 %, 22.14 %) for tibial plateau fractures, and 1.07 % (-2.45 %, 4.59 %) for appendectomy.Conclusions: We found no significant effects of a targeted hospital funding model based on fixed price and volume on wait times or the provision of after-hours surgery. Other approaches for improving hip fracture wait times may be worth pursuing instead of funding reform. [ABSTRACT FROM AUTHOR]

Introduction: Dentists are a common source of opioid exposure. This study investigates the association between initial dental opioid prescription characteristics and subsequent persistent use and examines the rate of opioid overdose after initiation.Methods: A retrospective cohort study was conducted among Ontario residents who were dispensed an initial opioid prescription originating from a dentist between October 2014 and September 2018 (data were analyzed in October 2019-May 2020). Exposures were characterized on the basis of the average daily dose in milligram morphine equivalents and the duration and formulation (long versus short acting) of the initial prescription. New, persistent use was defined as ≥1 opioid prescription within 90 days and another within 91-365 days after the initial prescription. The rate of an opioid overdose within 90 days after initiation was examined.Results: Among 786,125 Ontarians who initiated a dentist-prescribed opioid, 34,880 (4.4%) developed persistent use, whereas 140 (0.72 per 1,000 person-years) had evidence of an overdose within 90 days. People dispensed an initial daily dose >90 milligram morphine equivalents (n=5,644, 0.7%) had significantly greater odds of persistence (AOR=1.20, 95% CI=1.07, 1.34) than those dispensed ≤20 milligram morphine equivalents (n=179,884, 22.9%). Persistence was also significantly associated with receiving longer prescription durations and a long-acting opioid on initiation.Conclusions: Among people who initiated a dentist-prescribed opioid, 1 in 23 experienced persistent use, and persistence was associated with the characteristics of the prescription. Prescribing lower doses, prescribing for shorter durations, and avoiding long-acting formulations may be an opportunity to lessen the risk of persistent opioid use. [ABSTRACT FROM AUTHOR]

Background: Stigma and high-care needs can present barriers to the provision of high-quality primary care for people with opioid use disorder (OUD) and those prescribed opioids for chronic pain. We explored the likelihood of securing a new primary care provider (PCP) among people with varying histories of opioid use who had recently lost access to their PCP.Methods and Findings: We conducted a retrospective cohort study using linked administrative data among residents of Ontario, Canada whose enrolment with a physician practicing in a primary care enrolment model (PEM) was terminated between January 2016 and December 2017. We assigned individuals to 3 groups based upon their opioid use on the date enrolment ended: long-term opioid pain therapy (OPT), opioid agonist therapy (OAT), or no opioid. We fit multivariable models assessing the primary outcome of primary care reattachment within 1 year, adjusting for demographic characteristics, clinical comorbidities, and health services utilization. Secondary outcomes included rates of emergency department (ED) visits and opioid toxicity events. Among 154,970 Ontarians who lost their PCP, 1,727 (1.1%) were OAT recipients, 3,644 (2.4%) were receiving long-term OPT, and 149,599 (96.5%) had no recent prescription opioid exposure. In general, OAT recipients were younger (median age 36) than those receiving long-term OPT (59 years) and those with no recent prescription opioid exposure (44 years). In all exposure groups, the majority of individuals had their enrolment terminated by their physician (range 78.1% to 88.8%). In the primary analysis, as compared to those not receiving opioids, OAT recipients were significantly less likely to find a PCP within 1 year (adjusted hazard ratio [aHR] 0.55, 95% confidence interval [CI] 0.50 to 0.61, p < 0.0001). We observed no significant difference between long-term OPT and opioid unexposed individuals (aHR 0.96; 95% CI 0.92 to 1.01, p = 0.12). In our secondary analysis comparing the period of PCP loss to the year prior, we found that rates of ED visits were elevated among people not receiving opioids (adjusted rate ratio (aRR) 1.20, 95% CI 1.18 to 1.22, p < 0.0001) and people receiving long-term OPT (aRR 1.37, 95% CI 1.28 to 1.48, p < 0.0001). We found no such increase among OAT recipients, and no significant increase in opioid toxicity events in the period following provider loss for any exposure group. The main limitation of our findings relates to their generalizability outside of PEMs and in jurisdictions with different financial incentives incorporated into primary care provision.Conclusions: In this study, we observed gaps in access to primary care among people who receive prescription opioids, particularly among OAT recipients. Ongoing efforts are needed to address the stigma, discrimination, and financial disincentives that may introduce barriers to the healthcare system, and to facilitate access to high-quality, consistent primary care services for chronic pain patients and those with OUD. [ABSTRACT FROM AUTHOR]

Aims: There are conflicting signals in the literature about comparative safety and effectiveness of direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (NVAF). Methods: We conducted multicentre matched cohort studies with secondary meta‐analysis to assess safety and effectiveness of dabigatran, rivaroxaban and apixaban across 9 administrative healthcare databases. We included adults with NVAF initiating anticoagulation therapy (dabigatran, rivaroxaban or apixaban), and constructed 3 cohorts to compare DOACs pairwise. The primary outcome was pooled hazard ratio (pHR) of ischaemic stroke or systemic thromboembolism. Secondary outcomes included pHR of major bleeding, and a composite of stroke, major bleeding, or all‐cause mortality. We used proportional hazard Cox regressions models, and pooled estimates were obtained with random effect meta‐analyses. Results: The cohorts included 73 414 new users of dabigatran, 92 881 of rivaroxaban, and 61 284 of apixaban. After matching, the pHRs (95% confidence intervals) comparing rivaroxaban initiation to dabigatran were: 1.11 (0.93, 1.32) for ischaemic stroke or systemic thromboembolism, 1.26 (1.09, 1.46) for major bleeding, and 1.17 (1.05, 1.30) for the composite endpoint. For apixaban vs dabigatran, they were: 0.91 (0.74, 1.12) for ischaemic stroke or systemic thromboembolism, 0.89 (0.75, 1.05) for major bleeding, and 0.94 (0.78 to 1.14) for the composite endpoint. For apixaban vs rivaroxaban, they were: 0.85 (0.74, 0.99) for ischaemic stroke or systemic thromboembolism, 0.61 (0.53, 0.70) for major bleeding, and 0.82 (0.76, 0.88) for the composite endpoint. Conclusion: We found that apixaban use is associated with lower risks of stroke and bleeding compared with rivaroxaban, and similar risks compared with dabigatran. [ABSTRACT FROM AUTHOR]

Background: Data on resuming oral anticoagulants (OACs) after bleeding are primarily from studies involving patients given warfarin, with few data on direct OACs (DOACs). We aimed to characterize prescribing patterns for OACs after OAC-related bleeding and compare the rates of bleeding, thrombosis and mortality in patients who resumed either type of OAC with those who did not.Methods: We conducted a population-based cohort study of adults aged 66 years or older who were admitted to hospital for bleeding while receiving OACs from Apr. 1, 2012, to Mar. 31, 2017, using linked administrative health databases from Ontario. We used competing risk methods to calculate cause-specific adjusted hazard ratios (HRs) for thrombosis, bleeding and mortality with resumption of OACs adjusted as a time-varying covariate. We determined time to OAC resumption using the Kaplan-Meier method.Results: We included 6793 patients with gastrointestinal (n = 4297, 63.3%), intracranial (n = 805, 11.9%) or other bleeding (n = 1691, 25.0%). At cohort entry, 3874 patients (57.0%) were prescribed warfarin and 2919 patients (43.0%) were prescribed a DOAC. The most common indication for OAC was atrial fibrillation (n = 5557, 81.8%), followed by venous thromboembolism (n = 1367, 20.1%). Oral anticoagulants were resumed in 4792 patients (70.5%) within 365 days of the index bleed. The median time to resumption was 46 (interquartile range 6-550) days. We found that resuming OAC was associated with reduced rates of thrombosis (adjusted HR 0.60, 95% confidence interval [CI] 0.50-0.72) and mortality (adjusted HR 0.54, 95% CI 0.48-0.60), and an increased rate of rebleeding (adjusted HR 1.88, 95% CI 1.64-2.17).Interpretation: We found that resuming OAC is associated with a reduction in thrombosis and mortality but an increase in bleeding. Randomized controlled trials that evaluate the net benefit of strategies for resumption of OAC after a bleeding event are warranted. [ABSTRACT FROM AUTHOR]

Background: Health interventions and policies for high-cost health care users (HCUs) who are older adults need to be informed by a better understanding of their multimorbidity and medication use. This study aims to determine the financial contribution of medications to HCU expenditures and explore whether potentially inappropriate prescribing is associated with incident HCU development. Methods: This is a protocol for a retrospective population-based matched cohort analysis of incident older adult HCUs (those with the highest 5% of costs and 66 years of age or older) in Ontario during fiscal year 2013. We will obtain person-level data for the index year and year before HCU status from health administrative databases and match each HCU to 3 non-HCUs based on age, sex and geographic location. Average annual medication costs (per patient) and the ratio of medication to total health care costs (at population level) will be examined over the HCU transition period and compared with non-HCUs. We will explore potential quality improvement areas for prescribing by analyzing chronic conditions and the use of medications with a strong evidence base for either clinical benefit or risk of harms outweighing benefits in older adults with these diagnoses. The relation between these medication classes and incident HCU status will be explored using logistic regression. Interpretation: Using a matched cohort design and focusing on incident rather than prevalent HCUs, this protocol will explore our hypotheses that medications and the quality of their prescribing may be important triggers of HCU status and facilitate the identification of potential preventive clinical interventions or policies. Dissemination of results will occur via publications in peer-reviewed journals, presentations at conferences and academic settings, and knowledge translation activities with relevant health system and patient stakeholder groups. Study registration: Clinicaltrials.gov, no. NCT02815930 [ABSTRACT FROM AUTHOR]

Background: Mortality after bariatric surgery has been previously studied, but cohort selection bias, completeness of follow-up, and collection of confounders have limited the inference of results. Objective: To determine the association between bariatric surgery and all-cause mortality. Design: Population-based matched cohort study. Setting: Ontario, Canada. Participants: 13 679 patients who underwent bariatric surgery from January 2010 to December 2016 and 13 679 matched nonsurgical patients. Intervention: Bariatric surgery. Measurements: The primary outcome was all-cause mortality, with cause-specific mortality as the secondary outcome. Patients were matched according to age, sex, body mass index, and diabetes duration. Results: 13 679 patients who underwent bariatric surgery were matched to 13 679 nonsurgical patients. After a median follow-up of 4.9 years, the overall mortality rate was 1.4% (n  = 197) in the surgery group and 2.5% (n  = 340) in the nonsurgery group, with a lower adjusted hazard ratio (HR) of overall all-cause mortality (HR, 0.68 [95% CI, 0.57 to 0.81]). Patients aged 55 years or older had an absolute risk reduction of 3.3% (CI, 2.3% to 4.3%), with a lower HR of mortality in the surgery group (HR, 0.53 [CI, 0.41 to 0.69]). Observed relative effects were similar across sex; however, the observed association in absolute terms was greater in men. Surgery also was associated with lower cardiovascular mortality (HR, 0.53 [CI, 0.34 to 0.84]) and lower cancer mortality (HR, 0.54 [CI, 0.36 to 0.80]). Limitation: The observational design limits causal inference. Conclusion: Bariatric surgery was associated with substantially lower all-cause, cardiovascular, and cancer mortality. The lowered observed mortality of surgery was significant across most subgroups. The largest absolute effects were for men and patients aged 55 years or older. Primary Funding Source: Ontario Bariatric Network. Visual Abstract. Association Between Bariatric Surgery and All-Cause Mortality This study compared risk for death among patients who had bariatric surgery versus nonsurgical control patients and examined this relationship across subgroups based on age and other characteristics. This study compared risk for death among patients who had bariatric surgery versus nonsurgical control patients and examined this relationship across subgroups based on age and other characteristics. [ABSTRACT FROM AUTHOR]

Background: Direct oral anticoagulants (DOACs) have widely replaced warfarin for stroke prevention in nonvalvular atrial fibrillation. Our objective was to compare the safety and effectiveness of DOACs (dabigatran, rivaroxaban, apixaban) versus warfarin for stroke prevention in nonvalvular atrial fibrillation in the Canadian setting. Methods: We conducted a population-based observational multicentre cohort study with propensity score matching and subsequent meta-analysis. We used health care databases from 7 Canadian provinces (British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec and Nova Scotia). Patients with nonvalvular atrial fibrillation who initiated anticoagulation therapy in 2009–2017 were matched to an equal number who initiated warfarin. The primary outcome was the pooled hazard ratio (HR) for ischemic stroke or systemic embolization. Secondary outcomes included pooled HRs for major bleeding; a composite outcome of stroke, systemic embolization, major bleeding and all-cause mortality; and myocardial infarction. We modelled HRs using proportional hazard Cox regression with inverse probability of censoring weights, and estimated pooled HRs with random-effect meta-analyses. Results: We included 128 273 patients who initiated anticoagulation with a DOAC (40 503 dabigatran, 49 498 rivaroxaban and 38 272 apixaban) and 128 273 patients who initiated anticoagulation with warfarin. The pooled HR for ischemic stroke or systemic embolization comparing DOACs to warfarin was 1.02 (95% confidence interval [CI] 0.87 to 1.19). Direct oral anticoagulants were associated with lower rates of major bleeding (pooled HR 0.81, 95% CI 0.69 to 0.97), the composite outcome (pooled HR 0.81, 95% CI 0.74 to 0.89) and all-cause mortality (pooled HR 0.81, 95% CI 0.78 to 0.85). Interpretation: In this real-world study, DOACs were associated with similar risks of ischemic stroke or systemic embolization, and lower risks of bleeding and total mortality compared to warfarin. These findings support the use of DOACs for anticoagulation in nonvalvular atrial fibrillation. Trial registration: ClinicalTrials.gov, no. NCT03596502 [ABSTRACT FROM AUTHOR]

Background: The Government of Ontario, Canada, announced hospital funding reforms in 2011, including Quality-based Procedures (QBPs) involving pre-set funds for managing patients with specific diagnoses/procedures. A key goal was to improve quality of care across the jurisdiction. Methods: Interrupted time series evaluated the policy change, focusing on four QBPs (congestive heart failure, hip fracture surgery, pneumonia, prostate cancer surgery), on patients hospitalized 2010–2017. Outcomes included return to hospital or death within 30 days, acute length of stay (LOS), volume of admissions, and patient characteristics. Results: At 2 years post-QBPs, the percentage of hip fracture patients who returned to hospital or died was 3.13% higher in absolute terms (95% CI: 0.37% to 5.89%) than if QBPs had not been introduced. There were no other statistically significant changes for return to hospital or death. For LOS, the only statistically significant change was an increase for prostate cancer surgery of 0.33 days (95% CI: 0.07 to 0.59). Volume increased for congestive heart failure admissions by 80 patients (95% CI: 2 to 159) and decreased for hip fracture surgery by 138 patients (95% CI: -183 to -93) but did not change for pneumonia or prostate cancer surgery. The percentage of patients who lived in the lowest neighborhood income quintile increased slightly for those diagnosed with congestive heart failure (1.89%; 95% CI: 0.51% to 3.27%) and decreased for those who underwent prostate cancer surgery (-2.08%; 95% CI: -3.74% to -0.43%). Interpretation: This policy initiative involving a change to hospital funding for certain conditions was not associated with substantial, jurisdictional-level changes in access or quality. [ABSTRACT FROM AUTHOR]

Background: In pandemics, local hospitals need to anticipate a surge in health care needs. We examined the modelled surge because of the coronavirus disease 2019 (COVID-19) pandemic that was used to inform the early hospital-level response against cases as they transpired. Methods: To estimate hospital-level surge in March and April 2020, we simulated a range of scenarios of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread in the Greater Toronto Area (GTA), Canada, using the best available data at the time. We applied outputs to hospital-specific data to estimate surge over 6 weeks at 2 hospitals (St. Michael's Hospital and St. Joseph's Health Centre). We examined multiple scenarios, wherein the default (R0 = 2.4) resembled the early trajectory (to Mar. 25, 2020), and compared the default model projections with observed COVID-19 admissions in each hospital from Mar. 25 to May 6, 2020. Results: For the hospitals to remain below non-ICU bed capacity, the default pessimistic scenario required a reduction in non-COVID-19 inpatient care by 38% and 28%, respectively, with St. Michael's Hospital requiring 40 new ICU beds and St. Joseph's Health Centre reducing its ICU beds for non-COVID-19 care by 6%. The absolute difference between default-projected and observed census of inpatients with COVID-19 at each hospital was less than 20 from Mar. 25 to Apr. 11; projected and observed cases diverged widely thereafter. Uncertainty in local epidemiological features was more influential than uncertainty in clinical severity. Interpretation: Scenario-based analyses were reliable in estimating short-term cases, but would require frequent re-analyses. Distribution of the city's surge was expected to vary across hospitals, and community-level strategies were key to mitigating each hospital's surge. [ABSTRACT FROM AUTHOR]

Background Context: An important step in improving spinal care is understanding how current health-care resources and associated cost are being utilized and distributed across a health-care system.Purpose: Our objective was to examine the magnitude and distribution of direct health care costs for spinal conditions across physician type and hospital setting.Design/setting: Cross-sectional analysis of administrative health data for the fiscal year 2013-2014 from the province of Ontario, Canada.Patient Sample: Adult population aged 18+ years (N=10,841,302).Outcome Measures: Person visit rates and total number of people and visits by specific care settings were calculated for all spinal conditions as well as stratified by nontrauma and trauma-related conditions. Variation in rates by age and sex was examined. The proportion of patients seeing physicians of different specialties was calculated for each condition grouping. Direct medical costs were estimated and their percentage distribution by care setting calculated for nontrauma and trauma-related conditions. Additionally, costs for spinal imaging overall and stratified by type of scan were determined.Methods: Administrative health databases were analyzed, including data on physician services, emergency department visits, and hospitalizations. ICD-9 and -10 diagnostic codes were used to identify nontraumatic (degenerative or inflammatory) and traumatic spinal disorders. A validated algorithm was used to estimate direct medical costs.Results: Overall, 822,000 adult Ontarians (7.6%) made 1.6 million outpatient physician visits for spinal conditions; the majority (1.1 million) of these visits were for nontrauma conditions. Approximately, 86% of outpatient visits were in primary care. Emergency Department (ED) visits for nontrauma spinal conditions (130,000 out of 156,000 ED visits) accounted for 2.8% of all ED visits in the province. Total costs for spine-related care were $264 million (CDN) with 64% of costs due to nontrauma conditions. For these nontrauma conditions, ED visits cost $28 million for 130,000 visits ($215 per visit). For $32 million spent in primary care, 890,000 visits were made ($36 per visit). Spine imaging costs were $66.5 million, yielding a combined total of $330 million in health care spending for spinal conditions.Conclusions: Spinal conditions place a large and costly burden on the health-care system. The disproportionate annual cost associated with ED visits represents a potential opportunity to redirect costs to fund more clinically and cost-effective models of care for nontraumatic spinal conditions. [ABSTRACT FROM AUTHOR]

Background: Regulatory agencies warn about the risk of acute kidney injury (AKI) after the initiation of sodium-glucose cotransporter-2 (SGLT2) inhibitors. Our objective was to quantify the 90-day risk of AKI in older adults after initiation of SGLT2 inhibitors in routine clinical practice.Methods: We conducted a population-based retrospective cohort study in Ontario, Canada, involving adults with diabetes who were aged 66 years or older and who were newly dispensed either an SGLT2 inhibitor or a dipeptidyl peptidase-4 (DPP4) inhibitor in an outpatient setting between 2015 and 2017. We used inverse probability of treatment weighting based on a propensity score to balance the 2 groups on measured baseline characteristics. The primary outcome was 90-day risk of a hospital encounter (i.e., visit to the emergency department or admission to hospital) with AKI, which we defined by a 50% or greater increase in the concentration of serum creatinine from the baseline value or an absolute increase of at least 27 μmol/L after an SGLT2 or DDP4 inhibitor was dispensed. We obtained weighted risk ratios using modified Poisson regression and weighted risk differences using binomial regression.Results: We included 39 094 patients with a median age of 70 (interquartile range 68-74) years in the study. Relative to new use of a DPP4 inhibitor, initiation of a SGLT2 inhibitor was associated with a lower 90-day risk of a hospital encounter with AKI: 216 events in 19 611 patients (1.10%) versus 388 events in 19 483 patients (1.99%); weighted risk ratio 0.79 (95% confidence interval 0.64-0.98).Interpretation: In routine care of older adults, new use of SGLT2 inhibitors compared with use of DPP4 inhibitors was associated with a lower risk of AKI. Together with previous evidence, our findings suggest that regulatory warnings about AKI risk with SGLT2 inhibitors are unwarranted. [ABSTRACT FROM AUTHOR]

Background: Invasive fungal infection (IFI) in solid organ transplant (SOT) recipients is associated with significant morbidity and mortality. The long‐term probability of post‐transplant IFI is poorly understood. Methods: We conducted a population‐based cohort study using linked administrative healthcare databases from Ontario, Canada, to determine the incidence rate; 1‐, 5‐, and 10‐year cumulative probabilities of IFI; and post‐IFI all‐cause mortality in SOT recipients from 2002 to 2016. We also determined post‐IFI, death‐censored renal allograft failure. Results: We included 9326 SOT recipients (median follow‐up: 5.35 years). Overall, the incidence of IFI was 8.3 per 1000 person‐years. The 1‐year cumulative probability of IFI was 7.4% for lung, 5.4% for heart, 1.8% for liver, 1.2% for kidney‐pancreas, and 1.1% for kidney‐only allograft recipients. Lung transplant recipients had the highest incidence rate and 10‐year probability of IFI: 43.0 per 1000 person‐years and 26.4%, respectively. The 1‐year all‐cause mortality rate after IFI was 34.3%. IFI significantly increased the risk of mortality in SOT recipients over the entire follow‐up period (hazard ratio: 6.50, 95% CI: 5.69‐7.42). The 1‐year probability of death‐censored renal allograft failure after IFI was 9.8%. Conclusion: Long‐term cumulative probability of IFI varies widely among SOT recipients. Lung transplantation was associated with the highest incidence of IFI with considerable 1‐year all‐cause mortality. [ABSTRACT FROM AUTHOR]

Background: Unplanned visits to the emergency department after total joint arthroplasty are far more common than unplanned readmissions. Our objectives were to characterize the prevalence of presentation to an emergency department for any reason after total joint arthroplasty and to identify risk factors for such visits. Methods: Using health administrative databases, we conducted a population-based retrospective cohort study of adults (19–89 yr of age) who received their first primary elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) procedure for arthritis between April 2011 and March 2016 in Ontario. We made univariate comparisons between patients who presented to the emergency department within 30 days of surgery and those who did not in. We determined differences in use of health care services between groups by comparing the change in use in the year before and after surgery between patients who presented to the emergency department and those who did not. We developed logistic regression models for the occurrence of an emergency department visit using backward variable elimination. Results: We identified 42 273 total hip recipients and 70 725 total knee recipients, of whom 5640 (13.3%) and 11 224 (15.9%), respectively, presented to the emergency department within 30 days of surgery. Fewer than 1% of these patients required admission, and nearly half (45%) went to a different institution from where they had their surgery. Among both THA and TKA recipients, patients who presented to the emergency department had a net increase in their median annual health care costs (THA: $501, TKA: $682), compared to a net decrease for the cohort as a whole. Factors associated with increased risk of an emergency visit included increased patient age, male sex, rural residence and various comorbidities. Predictive regression models showed poor discriminative ability for both THA (C-statistic 0.57) and TKA (C-statistic 0.58) recipients. Interpretation: One in 7 patients presented to the emergency department within 30 days of THA or TKA. Some may conceivably have been managed remotely, and very few required readmission. There is a crucial need for strategies to minimize these events. [ABSTRACT FROM AUTHOR]