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Objectives: There is a high prevalence of HIV (5.2% in 2018) among men who have sex with men (MSM) in Ukraine. HIV testing, condom provision and facilitated linkage to HIV treatment have been funded by various bodies through non‐governmental organizations (NGOs). We investigated whether contact with these NGOs was associated with improved prevention and treatment outcomes among MSM in Ukraine. Methods: Data were taken from four rounds of integrated bio‐behavioural surveys among MSM in Ukraine (2011, N = 5950; 2013, N = 8101; 2015, N = 4550; 2018, N = 5971) including HIV testing combined with questionnaire responses. Data were analysed using mixed‐effect regression models, which estimated associations between being an NGO client and behavioural, HIV testing and HIV treatment outcomes, adjusted for demographic factors. Results: Those MSM who were NGO clients were more likely than non‐clients to have been HIV tested in the last year [adjusted odds ratio (aOR) = 7.01, 95% confidence interval (CI): 6.45–7.62] or ever (aOR = 11.00, 95% CI: 9.77–12.38), to have used a condom for the last anal sex act (aOR = 1.32, 95% CI: 1.21–1.43), and to have recently either bought or received condoms (aOR = 21.27, 95% CI: 18.01–25.12). HIV‐positive MSM were more likely to have contact with NGOs (aOR = 1.61, 95% CI: 1.39–1.86). Among the HIV‐positive MSM, those who were NGO clients were more likely to be registered at an AIDS centre (aOR = 2.24, 95% CI: 1.61–3.11) and to be on antiretroviral treatment (aOR = 2.20, 95% CI: 1.51–3.20). Conclusions: In Ukraine, being in contact with MSM‐targeted NGOs is associated with better outcomes for HIV prevention, testing and treatment, suggesting that NGO harm reduction projects for MSM have had a beneficial impact on reducing HIV transmission and morbidity. [ABSTRACT FROM AUTHOR]

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New direct-acting antivirals have the potential to transform the hepatitis C ( HCV) treatment landscape, with rates of sustained viral response in excess of 90%. As these new agents are expensive, an important question is whether to focus on minimizing the consequences of severe liver disease, or reducing transmission via 'treatment as prevention'. A back-calculation model was used to estimate the impact of treatment of mild, moderate and compensated cirrhosis on incident cases of HCV-related end-stage liver disease/hepatocellular carcinoma ( ESLD/ HCC). In addition, a dynamic model was used to determine the impact on incidence and prevalence of chronic infection in people who inject drugs ( PWID), the main risk group in England. Treating 3500 cirrhotics per year was predicted to reduce ESLD/ HCC incidence from 1100 (95% CrI 970-1240) cases per year in 2015 to 630 (95% CrI 530-770) in 2020, around half that currently expected, although treating moderate-stage disease will also be needed to sustain this reduction. Treating mild-stage PWID was required to make a substantial impact on transmission: with 2500 treated per year, chronic prevalence/annual incidence in PWID was reduced from 34%/4.8% in 2015 to 11%/1.4% in 2030. There was little overlap between the two goals: treating mild stage had virtually no impact on ESLD/ HCC within 15 years, but the long timescale of liver disease means relatively few PWID reach cirrhosis before cessation of injecting. Strategies focussing on treating advanced disease have the potential for dramatic reductions in severe morbidity, but virtually no preventative impact. [ABSTRACT FROM AUTHOR]

Hepatitis C virus ( HCV) antiviral treatment for people who inject drugs ( PWID) could prevent onwards transmission and reduce chronic prevalence. We assessed current PWID treatment rates in seven UK settings and projected the potential impact of current and scaled-up treatment on HCV chronic prevalence. Data on number of PWID treated and sustained viral response rates ( SVR) were collected from seven UK settings: Bristol (37-48% HCV chronic prevalence among PWID), East London (37-48%), Manchester (48-56%), Nottingham (37-44%), Plymouth (30-37%), Dundee (20-27%) and North Wales (27-33%). A model of HCV transmission among PWID projected the 10-year impact of (i) current treatment rates and SVR (ii) scale-up with interferon-free direct acting antivirals ( IFN-free DAAs) with 90% SVR. Treatment rates varied from <5 to over 25 per 1000 PWID. Pooled intention-to-treat SVR for PWID were 45% genotypes 1/4 [95% CI 33-57%] and 61% genotypes 2/3 [95% CI 47-76%]. Projections of chronic HCV prevalence among PWID after 10 years of current levels of treatment overlapped substantially with current HCV prevalence estimates. Scaling-up treatment to 26/1000 PWID annually (achieved already in two sites) with IFN-free DAAs could achieve an observable absolute reduction in HCV chronic prevalence of at least 15% among PWID in all sites and greater than a halving in chronic HCV in Plymouth, Dundee and North Wales within a decade. Current treatment rates among PWID are unlikely to achieve observable reductions in HCV chronic prevalence over the next 10 years. Achievable scale-up, however, could lead to substantial reductions in HCV chronic prevalence. [ABSTRACT FROM AUTHOR]

summary Hepatitis C ( HCV) infection can cause cirrhosis, liver cancer and death in the absence of treatment. Many people living in the UK but born overseas are believed to be infected with HCV although many are unlikely to know they are infected. The aim of this study is to assess the potential for a case-finding approach to be cost-effective and to estimate the value of further research. An economic evaluation and value of information analysis was undertaken by developing a model of HCV disease progression and by populating it with evidence from the published literature. They were performed from a UK National Health Services cost perspective, and outcomes were expressed in terms of quality-adjusted life-years ( QALYs). The comparator intervention was defined as the background rate of testing (i.e. no intervention). The base case results generated an incremental cost-effectiveness ratio ( ICER) of about £23 200 per additional QALY. However, the ICER was shown to be particularly sensitive to HCV seroprevalence, the intervention effect / cost and the probability of treatment uptake. The value of information analysis suggested that approximately £4 million should be spent on further research. This evaluation demonstrates that testing UK migrants for HCV could be cost-effective. However, further research, particularly to refine estimates of the probability of treatment uptake once identified, the utility associated with sustained virological response and the cost of the intervention, would help to increase the robustness of this conclusion. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated the potential impact of hepatitis C virus (HCV) treatment on HCV infection prevalence among people who inject drugs (PWID) in Victoria using mathematical modelling. Researchers found that HCV infection prevalence could be halved, based on modest rates of current HCV treatment among PWID in Victoria. It concludes that interventions aimed at increasing access to HCV treatment will benefit individual PWID.

Background We consider how many cannabis users may need to be prevented in order to prevent one case of schizophrenia or psychosis [defined as number needed to prevent (NNP)]. Method Calculation for England and Wales using best available estimates of: incidence of schizophrenia; rates of heavy and light cannabis use; and risk that cannabis causes schizophrenia. Results In men the annual mean NNP for heavy cannabis and schizophrenia ranged from 2800 [90% confidence interval (CI) 2018-4530] in those aged 20-24 years to 4700 (90% CI 3114-8416) in those aged 35-39. In women, mean NNP for heavy cannabis use and schizophrenia ranged from 5470 (90% CI 3640-9839) in those aged 25-29 to 10 870 (90% CI 6786-22 732) in 35-39-year-olds. Equivalent mean NNP for heavy cannabis use and psychosis were lower, from 1360 (90% CI 1007-2124) in men aged 20-24 and 2480 (90% CI 1408-3518) in women aged 16-19. The mean and median number of light cannabis users that would need to be prevented in order to prevent one case of schizophrenia or psychosis per year are four to five times greater than among heavy users. Conclusions The number of young people who need to be exposed to an intervention to generate NNP and prevent one case of schizophrenia will be even larger. The public health importance of preventing cannabis to reduce schizophrenia or psychosis remains uncertain. More attention should be given to testing the hypothesis that cannabis is related causally to psychotic outcomes, and to considering what strategies will be the most effective in reducing heavy cannabis use among young people. [ABSTRACT FROM AUTHOR]

AIMS: To explore whether the low HIV prevalence observed in Bangladesh results from prevention activities, this study uses mathematical modelling to estimate the impact of a needle/syringe exchange intervention for injecting drug users (IDUs) in Dhaka, Bangladesh. DESIGN: Epidemiological, behavioural and intervention monitoring data were used to parameterize a dynamic mathematical model, and fit it to National HIV Sero-surveillance data among IDUs (2000-02). The model was used to estimate the impact of the intervention on HIV transmission among IDUs and their sexual partners. SETTING: Dhaka, Bangladesh, where the HIV prevalence has remained low despite high-risk sexual and injecting behaviours, and growing HIV epidemics in neighbouring countries. FINDINGS: The model predicts that the intervention may have reduced the incidence of HIV among IDUs by 90% (95% CI 74-94%), resulting in an IDU HIV prevalence of 10% (95% CI 4-19%) after 8 years of intervention activity instead of 42% (95% CI 30-47%) if the intervention had not occurred. CONCLUSIONS: The analysis highlights the potential for rapid HIV spread among IDUs in Dhaka, and suggests that the intervention may have substantially reduced IDU HIV transmission. However, there is no room for complacency. Sustained and expanded funding for interventions in Dhaka and other regions of Bangladesh are crucial to maintaining the low HIV prevalence. [ABSTRACT FROM AUTHOR]

The cover image, by Helen E Harris et al., is based on the Original Article New treatments for hepatitis C virus (HCV): scope for preventing liver disease and HCV transmission in England, DOI: 10.1111/jvh.12529. [ABSTRACT FROM AUTHOR]

Background and Aims: Although the evidence is uncertain, existing estimates for hepatitis C virus (HCV) in sub-Saharan Africa (SSA) indicate a high burden. We estimated HCV seroprevalence and viraemic prevalence among the general population in SSA., Methods: We searched Medline, Embase, Web of Science, APA PsycINFO, and World Health Organization Africa Index Medicus for community-based studies. Study quality was assessed using the Joanna Briggs Institute critical appraisal tool, and heterogeneity using the index of heterogeneity (I 2 ). Two approaches were deployed. First, we used random-effects meta-analysis to pool prevalence. Second, to derive representative estimates, we weighted each country's HCV seroprevalence using 2021 United Nations country population sizes., Results: We synthesized 130 studies. Overall, SSA HCV seroprevalence from the random-effects model was 4.17% (95% confidence interval [CI]: 3.71-4.66, I 2  = 99.30%). There were no differences between males (4.31%) and females (4.03%). Seroprevalence was 2.25%, 3.31%, and 16.23% for ages ≤20, 21-64, and ≥65 years, respectively, and was higher in rural (6.63%) versus urban (2.93%). There was indication of decrement overtime from 5.74% to 4.35% to 3.03% in the years 1984-2000, 2001-2014, and 2015-2023, respectively. The weighted overall SSA HCV seroprevalence was estimated to be 2.30% (95% CI: 1.59-3.00) with regional variation: Africa-Southern (.79%), Africa-Central (1.47%), Africa-Eastern (2.71%), and Africa-Western (2.88%). HCV viremia among HCV seropositives was 54.77% (95% CI: 47.80-61.66)., Conclusions: HCV seroprevalence in SSA remains high. Populations aged ≥65 years, rural communities, Africa-Western, and some countries in Africa-Central and Africa-Eastern appear disproportionately affected. These results underline the need for governmental commitment to achieve the 2030 global HCV elimination targets., (© 2024 The Author(s). Liver International published by John Wiley & Sons Ltd.)

Issues: Overdose prevention centres (OPC) are non-residential spaces where people can use illicit drugs (that they have obtained elsewhere) in the presence of staff who can intervene to prevent and manage any overdoses that occur. Many reviews of OPCs exist but they do not explain how OPCs work., Approach: We carried out a realist review, using the RAMESES reporting standards. We systematically searched for and then thematically analysed 391 documents that provide information on the contexts, mechanisms and outcomes of OPCs., Key Findings: Our retroductive analysis identified a causal pathway that highlights the feeling of safety - and the immediate outcome of not dying - as conditions of possibility for the people who use OPCs to build trust and experience social inclusion. The combination of safety, trust and social inclusion that is triggered by OPCs can - depending on the contexts in which they operate - generate other positive outcomes, which may include less risky drug use practices, reductions in blood borne viruses and injection-related infections and wounds, and access to housing. These outcomes are contingent on relevant contexts, including political and legal environments, which differ for women and people from racialised minorities., Conclusions: OPCs can enable people who live with structural violence and vulnerability to develop feelings of safety and trust that help them stay alive and to build longer term trajectories of social inclusion, with potential to improve other aspects of their health and living conditions., (© 2024 The Author(s). Drug and Alcohol Review published by John Wiley & Sons Australia, Ltd on behalf of Australasian Professional Society on Alcohol and other Drugs.)

Background and Aims: The INTRO-HCV randomized controlled trial conducted in Norway over 2017-2019 found that integrated treatment, compared with standard-of-care hospital treatment, for hepatitis C virus (HCV) with direct-acting antivirals (DAAs) improved treatment outcomes among people who inject drugs (PWID). We evaluated cost-effectiveness of the INTRO-HCV intervention., Design: A Markov health state transition model of HCV disease progression and treatment with cost-effectiveness analysis from the health-provider perspective. Primary cost, utility, and health outcome data were derived from the trial. Costs and health benefits (quality-adjusted life-years, QALYs) were tracked over 50 years. Probabilistic and univariate sensitivity analyses investigated DAA price reductions and variations in HCV treatment and disease care cost assumptions, using costs from different countries (Norway, United Kingdom, United States, France, Australia)., Setting and Participants: PWID attending community-based drug treatment centers for people with opioid dependence in Norway., Measurements: Incremental cost-effectiveness ratio (ICER) in terms of cost per QALY gained, compared against a conventional (€70 000/QALY) willingness-to-pay threshold for Norway and lower (€20 000/QALY) threshold common among high-income countries., Findings: Integrated treatment resulted in an ICER of €13 300/QALY gained, with 99% and 71% probability of being cost-effective against conventional and lower willingness-to-pay thresholds, respectively. A 30% lower DAA price reduced the ICER to €6 900/QALY gained, with 91% probability of being cost-effective at the lower willingness-to-pay threshold. A 60% and 90% lower DAA price had 36% and >99% probability of being cost-saving, respectively. Sensitivity analyses suggest integrated treatment was cost-effective at the lower willingness-to-pay threshold (>60% probability) across different assumptions on HCV treatment and disease care costs with 30% DAA price reduction, and became cost-saving with 60%-90% price reductions., Conclusions: Integrated hepatitis C virus treatment for people who inject drugs in community settings is likely cost-effective compared with standard-of-care referral pathways in Norway and may be cost-saving in settings with particular characteristics., (© 2023 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Aims: We measured the association between a history of incarceration and HIV positivity among people who inject drugs (PWID) across Europe., Design, Setting and Participants: This was a cross-sectional, multi-site, multi-year propensity-score matched analysis conducted in Europe. Participants comprised community-recruited PWID who reported a recent injection (within the last 12 months)., Measurements: Data on incarceration history, demographics, substance use, sexual behavior and harm reduction service use originated from cross-sectional studies among PWID in Europe. Our primary outcome was HIV status. Generalized linear mixed models and propensity-score matching were used to compare HIV status between ever- and never-incarcerated PWID., Findings: Among 43 807 PWID from 82 studies surveyed (in 22 sites and 13 countries), 58.7% reported having ever been in prison and 7.16% (n = 3099) tested HIV-positive. Incarceration was associated with 30% higher odds of HIV infection [adjusted odds ratio (aOR) = 1.32, 95% confidence interval (CI) = 1.09-1.59]; the association between a history of incarceration and HIV infection was strongest among PWID, with the lowest estimated propensity-score for having a history of incarceration (aOR = 1.78, 95% CI = 1.47-2.16). Additionally, mainly injecting cocaine and/or opioids (aOR = 2.16, 95% CI = 1.33-3.53), increased duration of injecting drugs (per 8 years aOR = 1.31, 95% CI = 1.16-1.48), ever sharing needles/syringes (aOR = 1.91, 95% CI = 1.59-2.28) and increased income inequality among the general population (measured by the Gini index, aOR = 1.34, 95% CI = 1.18-1.51) were associated with a higher odds of HIV infection. Older age (per 8 years aOR = 0.84, 95% CI = 0.76-0.94), male sex (aOR = 0.77, 95% CI = 0.65-0.91) and reporting pharmacies as the main source of clean syringes (aOR = 0.72, 95% CI = 0.59-0.88) were associated with lower odds of HIV positivity., Conclusions: A history of incarceration appears to be independently associated with HIV infection among people who inject drugs (PWID) in Europe, with a stronger effect among PWID with lower probability of incarceration., (© 2023 Society for the Study of Addiction.)

Background & Aims: People who inject drugs (PWID) experience high incarceration rates which are associated with increased hepatitis C virus (HCV) transmission risk. We assess the importance of prison-based interventions for achieving HCV elimination among PWID in New South Wales (NSW), Australia., Methods: A model of incarceration and HCV transmission among PWID was calibrated in a Bayesian framework to epidemiological and incarceration data from NSW, incorporating elevated HCV acquisition risk among recently released PWID. We projected the contribution of differences in transmission risk during/following incarceration to HCV transmission over 2020-2029. We estimated the past and potential future impact of prison-based opioid agonist therapy (OAT; ~33% coverage) and HCV treatment (1500 treatments in 2019 with 32.9%-83.3% among PWID) on HCV transmission. We estimated the time until HCV incidence reduces by 80% (WHO elimination target) compared to 2016 levels with or without prison-based interventions., Results: Over 2020-2029, incarceration will contribute 23.0% (17.9-30.5) of new HCV infections. If prison-based interventions had not been implemented since 2010, HCV incidence in 2020 would have been 29.7% (95% credibility interval: 22.4-36.1) higher. If current prison and community HCV treatment rates continue, there is an 98.8% probability that elimination targets will be achieved by 2030, with this decreasing to 10.1% without current prison-based interventions., Conclusions: Existing prison-based interventions in NSW are critical components of strategies to reduce HCV incidence among PWID. Prison-based interventions are likely to be pivotal for achieving HCV elimination targets among PWID by 2030., (© 2022 The Authors. Liver International published by John Wiley & Sons Ltd.)

Background and Aims: In 2015, the country of Georgia launched an elimination program aiming to reduce the prevalence of Hepatitis C virus (HCV) infection by 90% from 5.4% prevalence (~150 000 people). During the first 2.5 years of the program, 770 832 people were screened, 48 575 were diagnosed with active HCV infection, and 41 483 patients were treated with direct-acting antiviral (DAA)-based regimens, with a >95% cure rate., Methods: We modelled the incremental cost-effectiveness ratio (ICER) of HCV screening, diagnosis and treatment between April 2015 and November 2017 compared to no treatment, in terms of cost per quality-adjusted life year (QALY) gained in 2017 US dollars, with a 3% discount rate over 25 years. We compared the ICER to willingness-to-pay (WTP) thresholds of US$4357 (GDP) and US$871 (opportunity cost) per QALY gained., Results: The average cost of screening, HCV viremia testing, and treatment per patient treated was $386 to the provider, $225 to the patient and $1042 for generic DAAs. At 3% discount, 0.57 QALYs were gained per patient treated. The ICER from the perspective of the provider including generic DAAs was $2285 per QALY gained, which is cost-effective at the $4357 WTP threshold, while if patient costs are included, it is just above the threshold at $4398/QALY. All other scenarios examined in sensitivity analyses remain cost-effective except for assuming a shorter time horizon to the end of 2025 or including the list price DAA cost. Reducing or excluding DAA costs reduced the ICER below the opportunity-cost WTP threshold., Conclusions: The Georgian HCV elimination program provides valuable evidence that national programs for scaling up HCV screening and treatment for achieving HCV elimination can be cost-effective., (© 2022 The Authors. Liver International published by John Wiley & Sons Ltd.)

Background and Aims: The individual-level effectiveness of opioid agonist treatment (OAT) in reducing mortality is well established, but there is less evidence on population-level benefits. We use modeling informed with linked data from the OAT program in New South Wales (NSW), Australia, to estimate the impact of OAT provision in the community and prisons on mortality and the impact of eliminating excess mortality during OAT initiation/discontinuation., Design: Dynamic modeling., Setting and Participants: A cohort of 49 359 individuals who ever received OAT in NSW from 2001 to 2018., Measurements: Receipt of OAT was represented through five stages: (i) first month on OAT, (ii) short (1-9 months) and (iii) longer (9+ months) duration on OAT, (iv) first month following OAT discontinuation and (v) rest of time following OAT discontinuation. Incarceration was represented as four strata: (i) never or not incarcerated in the past year, (ii) currently incarcerated, (iii) released from prison within the past month and (iv) released from prison 1-12 months ago. The model incorporated elevated mortality post-release from prison and OAT impact on reducing mortality and incarceration., Findings: Among the cohort, mortality was 0.9 per 100 person-years, OAT coverage and retention remained high (> 50%, 1.74 years/episode). During 2001-20, we estimate that OAT provision reduced overdose and other cause mortality among the cohort by 52.8% [95% credible interval (CrI) = 49.4-56.9%] and 26.6% (95% CrI =22.1-30.5%), respectively. We estimate 1.2 deaths averted and 9.7 life-years gained per 100 person-years on OAT. Prison OAT with post-release OAT-linkage accounted for 12.4% (95% CrI = 11.5-13.5%) of all deaths averted by the OAT program, primarily through preventing deaths in the first month post-release. Preventing elevated mortality during OAT initiation and discontinuation could have averted up to 1.4% (95% CrI =  0.8-2.0%) and 3.0% (95% CrI = 2.1-5.3%) of deaths, respectively., Conclusion: The community and prison opioid agonist treatment program in New South Wales, Australia appears to have substantially reduced population-level overdose and all-cause mortality in the past 20 years, partially due to high retention., (© 2021 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Background and Aims: Hepatitis C virus (HCV) treatment is essential for eliminating HCV in people who inject drugs (PWID), but has limited coverage in resource-limited settings. We measured the cost-effectiveness of a pilot HCV screening and treatment intervention using directly observed therapy among PWID attending harm reduction services in Nairobi, Kenya., Design: We utilized an existing model of HIV and HCV transmission among current and former PWID in Nairobi to estimate the cost-effectiveness of screening and treatment for HCV, including prevention benefits versus no screening and treatment. The cure rate of treatment and costs for screening and treatment were estimated from intervention data, while other model parameters were derived from literature. Cost-effectiveness was evaluated over a life-time horizon from the health-care provider's perspective. One-way and probabilistic sensitivity analyses were performed., Setting: Nairobi, Kenya., Population: PWID., Measurements: Treatment costs, incremental cost-effectiveness ratio (cost per disability-adjusted life year averted)., Findings: The cost per disability-adjusted life-year averted for the intervention was $975, with 92.1% of the probabilistic sensitivity analyses simulations falling below the per capita gross domestic product for Kenya ($1509; commonly used as a suitable threshold for determining whether an intervention is cost-effective). However, the intervention was not cost-effective at the opportunity cost-based cost-effectiveness threshold of $647 per disability-adjusted life-year averted. Sensitivity analyses showed that the intervention could provide more value for money by including modelled estimates for HCV disease care costs, assuming lower drug prices ($75 instead of $728 per course) and excluding directly-observed therapy costs., Conclusions: The current strategy of screening and treatment for hepatitis C virus (HCV) among people who inject drugs in Nairobi is likely to be highly cost-effective with currently available cheaper drug prices, if directly-observed therapy is not used and HCV disease care costs are accounted for., (© 2021 Society for the Study of Addiction.)

Background and Aim: Globally, nearly one in five people who inject drugs (PWID) are living with HIV, and the rate of new HIV infections in PWID is increasing in some settings. Early diagnosis is crucial for effective HIV control. We reviewed the evidence on the association between opioid agonist therapy (OAT) and HIV testing uptake among PWID., Methods: We conducted a systematic review searching MEDLINE, Scopus, Web of Science, Cochrane Central Register of Controlled Trials and PsycINFO for studies published from January 2000 to March 2019. Reference lists and conference proceedings were hand-searched. Observational and intervention studies were eligible for inclusion. Risk of bias was assessed using the Risk of Bias in Non-Randomised Studies of Interventions (ROBINS-I) tool. Meta-analyses were conducted using random-effects models., Results: Of 13 373 records identified, 11 studies from Australia, Europe, Malaysia and the United States were included. All studies had at least a serious risk of bias, largely due to confounding and selection bias, making it difficult to draw causal conclusions from the evidence. Ten studies provided data on the association between current OAT use and recent HIV testing. Six showed a positive association, while four provided little evidence of an association: pooled odds ratio (OR) = 1.71, 95% confidence interval (CI) = 1.28-2.27. Looking at having ever been on OAT and having ever been HIV tested, seven studies showed a positive association and three showed either weak or no evidence of an association: pooled OR = 3.82, 95% CI = 2.96-4.95., Conclusions: Opioid agonist therapy may increase uptake of HIV testing among people who inject drugs, providing further evidence that opioid agonist therapy improves the HIV treatment care cascade., (© 2020 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Background & Aims: In 2016, Médecins Sans Frontières established the first general population Hepatitis C virus (HCV) screening and treatment site in Cambodia, offering free direct-acting antiviral (DAA) treatment. This study analysed the cost-effectiveness of this intervention., Methods: Costs, quality adjusted life years (QALYs) and cost-effectiveness of the intervention were projected with a Markov model over a lifetime horizon, discounted at 3%/year. Patient-level resource-use and outcome data, treatment costs, costs of HCV-related healthcare and EQ-5D-5L health states were collected from an observational cohort study evaluating the effectiveness of DAA treatment under full and simplified models of care compared to no treatment; other model parameters were derived from literature. Incremental cost-effectiveness ratios (cost/QALY gained) were compared to an opportunity cost-based willingness-to-pay threshold for Cambodia ($248/QALY)., Results: The total cost of testing and treatment per patient for the full model of care was $925(IQR $668-1631), reducing to $376(IQR $344-422) for the simplified model of care. EQ-5D-5L values varied by fibrosis stage: decompensated cirrhosis had the lowest value, values increased during and following treatment. The simplified model of care was cost saving compared to no treatment, while the full model of care, although cost-effective compared to no treatment ($187/QALY), cost an additional $14 485/QALY compared to the simplified model, above the willingness-to-pay threshold for Cambodia. This result is robust to variation in parameters., Conclusions: The simplified model of care was cost saving compared to no treatment, emphasizing the importance of simplifying pathways of care for improving access to HCV treatment in low-resource settings., (© 2020 The Authors. Liver International published by John Wiley & Sons Ltd.)

Background and Aims: People who inject drugs (PWID) are at high risk of hepatitis C virus (HCV) infection; however, ~50% are undiagnosed in England and linkage-to-care is poor. This study investigated the cost-effectiveness of an intervention (HepCATT) to improve case-finding and referral to HCV treatment compared with standard-of-care pathways in drug treatment centres in England., Design: HCV transmission and disease progression model with cost-effectiveness analysis using a health-care perspective. Primary outcome and cost data from the HepCATT study parameterized the intervention, suggesting that HepCATT increased HCV testing in drug treatment centres 2.5-fold and engagement onto the HCV treatment pathway 10-fold. A model was used to estimate the decrease in HCV infections and HCV-related deaths from 2016, with costs and health benefits (quality-adjusted life-years or QALYs) tracked over 50 years. Univariable and probabilistic sensitivity analyses (PSA) were undertaken., Setting: England-specific epidemic with 40% prevalence of chronic HCV among PWID., Participants: PWID attending drug treatment centres., Intervention: Nurse facilitator in drug treatment centres to improve the HCV care pathway from HCV case-finding to referral and linkage to specialist care. Comparator was the standard-of-care HCV care pathway., Measurements: Incremental cost-effectiveness ratio (ICER) in terms of cost per QALY gained through improved case-finding., Findings: Over 50 years per 1000 PWID, the HepCATT intervention could prevent 75 (95% central interval 37-129) deaths and 1330 (827-2040) or 51% (30-67%) of all new infections. The mean ICER was £7986 per QALY gained, with all PSA simulations being cost-effective at a £20 000 per QALY willingness-to-pay threshold. Univariable sensitivity analyses suggest the intervention would become cost-saving if the cost of HCV treatment reduces to £3900. If scaled up to all PWID in England, the intervention would cost £8.8 million and decrease incidence by 56% (33-70%) by 2030., Conclusions: Increasing hepatitis C virus infection case-finding and treatment referral in drug treatment centres could be a highly cost-effective strategy for decreasing hepatitis C virus incidence among people who inject drugs., (© 2020 Society for the Study of Addiction.)

Background and Aims: Traditional detachable syringes used by people who inject drugs (PWID) retain larger volumes of blood when the plunger is depressed than syringes with fixed needles-referred to as high (HDSS) and low dead space syringes (LDSS), respectively. Evidence suggests that using HDSS may result in greater hepatitis C virus (HCV) transmission risk than LDSS. We evaluated the cost-effectiveness of an intervention to introduce detachable LDSS in a needle and syringe programme (NSP)., Design: HCV transmission and disease progression model with cost-effectiveness analysis using a health-care perspective. Detachable LDSS are associated with increased costs (£0.008) per syringe, yearly staff training costs (£536) and an estimated decreased risk (by 47.5%) of HCV transmission compared with HDSS. The intervention was modelled for 10 years, with costs and health benefits (quality-adjusted life-years: QALYs) tracked over 50 years., Setting: Bristol, UK., Participants and Cases: PWID attending NSP., Intervention and Comparator: Gradual replacement of HDSS at NSP, with 8, 58 and 95% of HDSS being replaced by detachable LDSS in 2016, 2017 and 2018, respectively. Comparator was continuing use of HDSS., Measurements: Net monetary benefit. Benefits were measured in QALYs., Findings: Introducing detachable LDSS was associated with a small increase in intervention costs (£21 717) compared with not introducing detachable LDSS, but considerable savings in HCV-related treatment and care costs (£4 138 118). Overall cost savings were £4 116 401 over 50 years and QALY gains were 1000, with an estimated 30% reduction in new infections over the 10-year intervention period. In all sensitivity analyses, detachable LDSS resulted in cost savings and additional QALYs. Threshold analyses suggested that detachable LDSS would need to reduce HCV transmission risk of HDSS by 0.26% to be cost-saving and 0.04% to be cost-effective., Conclusions: Replacing high dead space syringes with detachable low dead space syringes in needle and syringe programmes in the United Kingdom is likely to be a cost-saving approach for reducing hepatitis C virus transmission., (© 2019 Society for the Study of Addiction.)

Backgrounds & Aims: In Indonesia 1.9 million people are chronically infected with hepatitis C virus (HCV), but a national strategic plan for elimination has not yet been developed, despite the availability of low-cost treatments which could save many lives. We used epidemiological and cost modelling to estimate targets and resource requirements of a national elimination program and explore the potential impact and cost-effectiveness., Methods: To model the HCV epidemic, we used a dynamic model, parameterised with Indonesia-specific data, accounting for disease progression, injecting drug use and demographics. Future scale-up scenarios were designed for 2018-2050 to capture possible policy choices. Costs of an initial 5-year national strategy and of long-term elimination were estimated for the most feasible scenario, as agreed with government and local partners. Cost savings from reduced drug and diagnostics prices were also estimated. The cost-effectiveness of baseline predictions and those with drug price reductions were compared to the no treatment scenario., Results: Elimination by 2045, considered the most feasible path to scale-up, would prevent 739 000 new infections and avert 158 000 HCV-related deaths. The costs would be $5.6 billion (USD) using baseline prices but could fall to $2.7 billion if price reductions for HCV drugs and diagnostics are secured. With these price reductions, the incremental cost-effectiveness ratio for a 2045 elimination program would be cost-effective at $300 (USD) per year of life saved vs the no treatment scenario., Conclusions: This study has underpinned advocacy efforts to secure Indonesian government commitment to HCV elimination, and provides further inputs for HCV strategic planning efforts., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Aims: To examine the cost-effectiveness of hepatitis C virus (HCV) treatment of people who inject drugs (PWID), combined with medication-assisted treatment (MAT) and syringe-service programs (SSP), to tackle the increasing HCV epidemic in the United States., Design: HCV transmission and disease progression models with cost-effectiveness analysis using a health-care perspective., Setting: Rural Perry County, KY (PC) and urban San Francisco, CA (SF), USA. Compared with PC, SF has a greater proportion of PWID with access to MAT or SSP. HCV treatment of PWID is negligible in both settings., Participants: PWID data were collected between 1998 and 2015 from Social Networks Among Appalachian People, U Find Out, Urban Health Study and National HIV Behavioral Surveillance System studies., Interventions and Comparator: Three intervention scenarios modeled: baseline-existing SSP and MAT coverage with HCV screening and treatment with direct-acting antiviral for ex-injectors only as per standard of care; intervention 1-scale-up of SSP and MAT without changes to treatment; and intervention 2-scale-up as intervention 1 combined with HCV screening and treatment for current PWID., Measurements: Incremental cost-effectiveness ratios (ICERs) and uncertainty using cost-effectiveness acceptability curves. Benefits were measured in quality-adjusted life-years (QALYs)., Findings: For both settings, intervention 2 is preferred to intervention 1 and the appropriate comparator for intervention 2 is the baseline scenario. Relative to baseline, for PC intervention 2 averts 1852 more HCV infections, increases QALYS by 3095, costs $21.6 million more and has an ICER of $6975/QALY. For SF, intervention 2 averts 36 473 more HCV infections, increases QALYs by 7893, costs $872 million more and has an ICER of $11 044/QALY. The cost-effectiveness of intervention 2 was robust to several sensitivity analysis., Conclusions: Hepatitis C screening and treatment for people who inject drugs, combined with medication-assisted treatment and syringe-service programs, is a cost-effective strategy for reducing hepatitis C burden in the United States., (© 2019 Society for the Study of Addiction.)

Aim: To evaluate the cost-effectiveness of needle and syringe programmes (NSPs) compared with no NSPs on hepatitis C virus (HCV) transmission in the United Kingdom., Design: Cost-effectiveness analysis from a National Health Service (NHS)/health-provider perspective, utilizing a dynamic transmission model of HCV infection and disease progression, calibrated using city-specific surveillance and survey data, and primary data collection on NSP costs. The effectiveness of NSPs preventing HCV acquisition was based on empirical evidence., Setting and Participants: UK settings with different chronic HCV prevalence among people who inject drugs (PWID): Dundee (26%), Walsall (18%) and Bristol (45%) INTERVENTIONS: Current NSP provision is compared with a counterfactual scenario where NSPs are removed for 10 years and then returned to existing levels with effects collected for 40 years., Measurements: HCV infections and cost per quality-adjusted life year (QALY) gained through NSPs over 50 years., Findings: Compared with a willingness-to-pay threshold of £20 000 per QALY gained, NSPs were highly cost-effective over a time-horizon of 50 years and decreased the number of HCV incident infections. The mean incremental cost-effectiveness ratio was cost-saving in Dundee and Bristol, and £596 per QALY gained in Walsall, with 78, 46 and 40% of simulations being cost-saving in each city, respectively, with differences driven by coverage of NSP and HCV prevalence (lowest in Walsall). More than 90% of simulations were cost-effective at the willingness-to-pay threshold. Results were robust to sensitivity analyses, including varying the time-horizon, HCV treatment cost and numbers of HCV treatments per year., Conclusions: Needle and syringe programmes are a highly effective low-cost intervention to reduce hepatitis C virus transmission, and in some settings they are cost-saving. Needle and syringe programmes are likely to remain cost-effective irrespective of changes in hepatitis C virus treatment cost and scale-up., (© 2019 Society for the Study of Addiction.)

Background and Aims: People who have recently injected drugs are a priority population in efforts to achieve hepatitis C virus (HCV) elimination. This study estimated the prevalence and number of people with recent injecting drug use living with HCV, and the proportion of people with recent injecting drug use among all people living with HCV infection at global, regional and country-levels., Methods: Data from a global systematic review of injecting drug use and HCV antibody prevalence among people with recent (previous year) injecting drug use were used to estimate the prevalence and number of people with recent injecting drug use living with HCV. These data were combined with a systematic review of global HCV prevalence to estimate the proportion of people with recent injecting drug use among all people living with HCV., Results: There are an estimated 6.1 million [95% uncertainty interval (UI) = 3.4-9.2] people with recent injecting drug use aged 15-64 years living with HCV globally (39.2% viraemic prevalence; UI = 31.6-47.0), with the greatest numbers in East and Southeast Asia (1.5 million, UI = 1.0-2.1), eastern Europe (1.5 million, UI = 0.7-2.4) and North America (1.0 million, UI = 0.4-1.7). People with recent injecting drug use comprise an estimated 8.5% (UI = 4.6-13.1) of all HCV infections globally, with the greatest proportions in North America (30.5%, UI = 11.7-56.7), Latin America (22.0%, UI = 15.3-30.4) and eastern Europe (17.9%, UI = 8.2-30.9)., Conclusions: Although, globally, 39.2% of people with recent injecting drug use are living with hepatitis C virus (HCV) and 8.5% of all HCV infections occur globally among people with recent injecting drug use, there is wide variation among countries and regions., (© 2018 Society for the Study of Addiction.)

Background and Aims: To reduce hepatitis C virus (HCV) transmission among people who inject drugs (PWID), Scottish Government-funded national strategies, launched in 2008, promoted scaling-up opioid substitution therapy (OST) and needle and syringe provision (NSP), with some increases in HCV treatment. We test whether observed decreases in HCV incidence post-2008 can be attributed to this intervention scale-up., Design: A dynamic HCV transmission model among PWID incorporating intervention scale-up and observed decreases in behavioural risk, calibrated to Scottish HCV prevalence and incidence data for 2008/09., Setting: Scotland, UK., Participants: PWID., Measurements: Model projections from 2008 to 2015 were compared with data to test whether they were consistent with observed decreases in HCV incidence among PWID while incorporating the observed intervention scale-up, and to determine the impact of scaling-up interventions on incidence., Findings: Without fitting to epidemiological data post-2008/09, the model incorporating observed intervention scale-up agreed with observed decreases in HCV incidence among PWID between 2008 and 2015, suggesting that HCV incidence decreased by 61.3% [95% credibility interval (CrI) = 45.1-75.3%] from 14.2/100 person-years (py) (9.0-20.7) to 5.5/100 py (2.9-9.2). On average, each model fit lay within 84% (10.1/12) of the confidence bounds for the 12 incidence data points against which the model was compared. We estimate that scale-up of interventions (OST + NSP + HCV treatment) and decreases in high-risk behaviour from 2008 to 2015 resulted in a 33.9% (23.8-44.6%) decrease in incidence, with the remainder [27.4% (17.6-37.0%)] explained by historical changes in OST + NSP coverage and risk pre-2008. Projections suggest that scaling-up of all interventions post-2008 averted 1492 (657-2646) infections over 7 years, with 1016 (308-1996), 404 (150-836) and 72 (27-137) due to scale-up of OST + NSP, decreases in high-risk behaviour and HCV treatment, respectively., Conclusions: Most of the decline in hepatitis C virus (HCV) incidence in Scotland between 2008 and 2015 appears to be attributable to intervention scale-up (opioid substitution therapy and needle and syringe provision) due to government strategies on HCV and drugs., (© 2018 Society for the Study of Addiction.)

Aims: To estimate whether opioid substitution treatment (OST) with buprenorphine or methadone is associated with a greater reduction in the risk of all-cause mortality (ACM) and opioid drug-related poisoning (DRP) mortality., Design: Cohort study with linkage between clinical records from Clinical Practice Research Datalink and mortality register., Setting: UK primary care., Participants: A total of 11 033 opioid-dependent patients who received OST from 1998 to 2014, followed-up for 30 410 person-years., Measurements: Exposure to methadone (17 373, 61%) OST episodes or buprenorphine (9173, 39%) OST episodes. ACM was available for all patients; information on cause of death and DRP was available for 5935 patients (54%) followed-up for 16 363 person-years. Poisson regression modelled mortality by treatment period with an interaction between OST type and treatment period (first 4 weeks on OST, rest of time off OST, first 4 weeks off OST, rest of time out of OST censored at 12 months) to test whether ACM or DRP differed between methadone and buprenorphine. Inverse probability weights were included to adjust for confounding and balance characteristics of patients prescribed methadone or buprenorphine., Findings: ACM and DRP rates were 1.93 and 0.53 per 100 person-years, respectively. DRP was elevated during the first 4 weeks of OST [incidence rate ratio (IRR) = 1.93 95% confidence interval (CI) = 0.97-3.82], the first 4 weeks off OST (IRR = 8.15, 95% CI = 5.45-12.19) and the rest of time out of OST (IRR = 2.13, 95% CI = 1.47-3.09) compared with mortality risk from 4 weeks to end of treatment. Patients on buprenorphine compared with methadone had lower ACM rates in each treatment period. After adjustment, there was evidence of a lower DRP risk for patients on buprenorphine compared with methadone at treatment initiation (IRR = 0.08, 95% CI = 0.01-0.48) and rest of time on treatment (IRR = 0.37, 95% CI = 0.17-0.79). Treatment duration (mean and median) was shorter on buprenorphine than methadone (173 and 40 versus 363 and 111, respectively). Model estimates suggest that there was a low probability that methadone or buprenorphine reduced the number of DRP in the population: 28 and 21%, respectively., Conclusions: In UK general medical practice, opioid substitution treatment with buprenorphine is associated with a lower risk of all-cause and drug-related poisoning mortality than methadone. In the population, buprenorphine is unlikely to give greater overall protection because of the relatively shorter duration of treatment., (© 2018 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Aims: To estimate the impact of existing high-coverage needle and syringe provision (HCNSP, defined as obtaining more than one sterile needle and syringe per injection reported) and opioid substitution therapy (OST) on hepatitis C virus (HCV) transmission among people who inject drugs (PWID) in three UK settings and to determine required scale-up of interventions, including HCV treatment, needed to reach the World Health Organization (WHO) target of reducing HCV incidence by 90% by 2030., Design: HCV transmission modelling using UK empirical estimates for effect of OST and/or HCNSP on individual risk of HCV acquisition., Setting and Participants: Three UK cities with varying chronic HCV prevalence (Bristol 45%, Dundee 26%, Walsall 19%), OST (72-81%) and HCNSP coverage (28-56%)., Measurements: Relative change in new HCV infections throughout 2016-30 if current interventions were stopped. Scale-up of HCNSP, OST and HCV treatment required to achieve the WHO elimination target., Findings: Removing HCNSP or OST would increase the number of new HCV infections throughout 2016 to 2030 by 23-64 and 92-483%, respectively. Conversely, scaling-up these interventions to 80% coverage could achieve a 29 or 49% reduction in Bristol and Walsall, respectively, whereas Dundee may achieve a 90% decrease in incidence with current levels of intervention because of existing high levels of HCV treatment (47-58 treatments per 1000 PWID). If OST and HCNSP are scaled-up, Walsall and Bristol can achieve the same impact by treating 14 or 40 per 1000 PWID annually, respectively (currently two and nine treatments per 1000 PWID), while 18 and 43 treatments per 1000 PWID would be required if OST and HCNSP are not scaled-up., Conclusions: Current opioid substitution therapy and high-coverage needle and syringe provision coverage is averting substantial hepatitis C transmission in the United Kingdom. Maintaining this coverage while getting current drug injectors onto treatment can reduce incidence by 90% by 2030., (© 2018 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Aims: To estimate the effects of needle and syringe programmes (NSP) and opioid substitution therapy (OST), alone or in combination, for preventing acquisition of hepatitis C virus (HCV) in people who inject drugs (PWID)., Methods: Systematic review and meta-analysis. Bibliographic databases were searched for studies measuring concurrent exposure to current OST (within the last 6 months) and/or NSP and HCV incidence among PWID. High NSP coverage was defined as regular NSP attendance or ≥ 100% coverage (receiving sufficient or greater number of needles and syringes per reported injecting frequency). Studies were assessed using the Cochrane risk of bias in non-randomized studies tool. Random-effects models were used in meta-analysis., Results: We identified 28 studies (n = 6279) in North America (13), United Kingdom (five), Europe (four), Australia (five) and China (one). Studies were at moderate (two), serious (17) critical (seven) and non-assessable risk of bias (two). Current OST is associated with 50% [risk ratio (RR) =0.50, 95% confidence interval (CI) = 0.40-0.63] reduction in HCV acquisition risk, consistent across region and with low heterogeneity (I 2  = 0, P = 0.889). Weaker evidence was found for high NSP coverage (RR = 0.79, 95% CI = 0.39-1.61) with high heterogeneity (I 2  = 77%, P = 0.002). After stratifying by region, high NSP coverage in Europe was associated with a 56% reduction in HCV acquisition risk (RR = 0.44, 95% CI = 0.24-0.80) with low heterogeneity (I 2  = 12.3%, P = 0.337), but not in North America (RR = 1.58, I 2  = 89.5%, P = < 0.001). Combined OST/NSP is associated with a 74% reduction in HCV acquisition risk (RR = 0.26, 95% CI = 0.07-0.89, I 2  = 80% P = 0.007). According to Grades of Recommendation Assessment, Development and Evaluation (GRADE) criteria, the evidence on OST and combined OST/NSP is low quality, while NSP is very low., Conclusions: Opioid substitution therapy reduces risk of hepatitis C acquisition and is strengthened in combination with needle and syringe programmes (NSP). There is weaker evidence for the impact of needle syringe programmes alone, although stronger evidence that high coverage is associated with reduced risk in Europe., (© 2017 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Background and Aims: Effective strategies are needed to address dramatic increases in hepatitis C virus (HCV) infection among people who inject drugs (PWID) in rural settings of the United States. We determined the required scale-up of HCV treatment with or without scale-up of HCV prevention interventions to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025 and 2030 in a rural US setting., Design: An ordinary differential equation model of HCV transmission calibrated to HCV epidemiological data obtained primarily from an HIV outbreak investigation in Indiana., Setting: Scott County, Indiana (population 24 181), USA, a rural setting with negligible baseline interventions, increasing HCV epidemic since 2010, and 55.3% chronic HCV prevalence among PWID in 2015., Participants: PWID., Measurements: Required annual HCV treatments per 1000 PWID (and initial annual percentage of infections treated) to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025/30, either with or without scaling-up syringe service programmes (SSPs) and medication-assisted treatment (MAT) to 50% coverage. Sensitivity analyses considered whether this impact could be achieved without re-treatment of re-infections, and whether greater intervention scale-up was required due to the increasing epidemic in this setting., Findings: To achieve a 90% reduction in incidence and prevalence by 2030, without MAT and SSP scale-up, 159 per 1000 PWID (initially 24.9% of infected PWID) need to be HCV-treated annually. However, with MAT and SSP scaled-up, treatment rates are halved (89 per 1000 annually or 14.5%). To reach the same target by 2025 with MAT and SSP scaled-up, 121 per 1000 PWID (19.9%) need treatment annually. These treatment requirements are threefold higher than if the epidemic was stable, and the impact targets are unattainable without retreatment., Conclusions: Combined scale-up of hepatitis C virus treatment and prevention interventions is needed to decrease the increasing burden of hepatitis C virus incidence and prevalence in rural Indiana, USA, by 90% by 2025/30., (© 2017 Society for the Study of Addiction.)

Aims: To project the impact of scaling-up oral anti-viral therapy and harm reduction on chronic hepatitis C (CHC) prevalence and incidence among people who inject drugs (PWID) in Greece, to estimate the relationship between required treatment levels and expansion of harm reduction programmes to achieve specific targets and to examine whether hepatitis C virus (HCV) elimination among PWID is possible in this high-prevalence setting., Design: A dynamic discrete time, stochastic individual-based model was developed to simulate HCV transmission among PWID incorporating the effect of HCV treatment and harm reduction strategies, and allowing for re-infection following treatment., Setting/participants: The population of 8300 PWID in Athens Metropolitan area., Measurements: Reduction in HCV prevalence and incidence in 2030 compared with 2016., Findings: Moderate expansion of HCV treatment (treating 4-8% of PWID/year), with a simultaneous increase of 2%/year in harm reduction coverage (from 44 to 72% coverage over 15 years), was projected to reduce CHC prevalence among PWID in Athens by 46.2-94.8% in 2030, compared with 2016. CHC prevalence would reduce to below 10% within the next 4-5 years if annual HCV treatment numbers were increased up to 16-20% PWID/year. The effect of harm reduction on incidence was more pronounced under lower treatment rates., Conclusions: Based on theoretical model projections, scaled-up hepatitis C virus treatment and harm reduction interventions could achieve major reductions in hepatitis C virus incidence and prevalence among people who inject drugs in Athens, Greece by 2030. Chronic hepatitis C could be eliminated in the next 4-5 years by increasing treatment to more than 16% of people who inject drugs per year combined with moderate increases in harm reduction coverage., (© 2017 Society for the Study of Addiction.)

Background and Aims: People who inject drugs (PWID) experience high incarceration rates, and previous incarceration is associated with elevated hepatitis C virus (HCV) transmission risk. In Scotland, national survey data indicate lower HCV incidence in prison than the community (4.3 versus 7.3 per 100 person-years), but a 2.3-fold elevated transmission risk among recently released (< 6 months) PWID. We evaluated the contribution of incarceration to HCV transmission among PWID and the impact of prison-related prevention interventions, including scaling-up direct-acting antivirals (DAAs) in prison., Design: Dynamic mathematical modelling of incarceration and HCV transmission, using approximate Bayesian computation for model calibration., Setting: Scotland, UK., Participants: A simulated population of PWID., Measurements: Population-attributable fraction (PAF) of incarceration to HCV transmission among PWID. Decrease in HCV incidence and chronic prevalence due to current levels of prison opiate substitution therapy (OST; 57% coverage) and HCV treatment, as well as scaling-up DAAs in prison and/or preventing the elevated risk associated with prison release., Findings: Incarceration contributes 27.7% [PAF; 95% credible interval (CrI) -3.1 to 51.1%] of HCV transmission among PWID in Scotland. During the next 15 years, current HCV treatment rates (10.4/6.8 per 1000 incarcerated/community PWID annually), with existing prison OST, could reduce incidence and chronic prevalence among all PWID by a relative 10.7% (95% CrI = 8.4-13.3%) and 9.7% (95% CrI = 7.7-12.1%), respectively. Conversely, without prison OST, HCV incidence and chronic prevalence would decrease by 3.1% (95% CrI = -28.5 to 18.0%) and 4.7% (95% CrI = -11.3 to 14.5%). Additionally, preventing the heightened risk among recently released PWID could reduce incidence and chronic prevalence by 45.0% (95% CrI = 19.7-57.5%) and 33.3% (95% CrI = 15.6-43.6%) or scaling-up prison HCV treatments to 80% of chronic PWID prison entrants with sufficient sentences (>16 weeks) could reduce incidence and prevalence by 45.6% (95% CrI = 38.0-51.3%) and 45.5% (95% CrI = 39.3-51.0%), respectively., Conclusions: Incarceration and the elevated transmission risk following prison release can contribute significantly to hepatitis C virus transmission among people who inject drugs. Scaling-up hepatitis C virus treatment in prison can provide important prevention benefits., (© 2017 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)

Aims: To assess systematically the risk of HIV acquisition by type of drug injected across different settings., Methods: A systematic review and meta-analysis were conducted. Databases were searched for studies of HIV incidence in people who inject different drugs (PWID). Pooled HIV incidence rate ratio (IRR) was used to compare HIV risk between injecting and not-injecting a given drug, when possible, or otherwise with those reported not to have injected the substance. Pooled estimates of crude IRR were derived using random-effects models. Variations in IRR were assessed in subgroup analyses, by drug and geographical region., Results: Of 5779 studies screened, 15 were included. HIV incidence was reported for people injecting cocaine (eight: North America, Europe), amphetamine-type stimulants (ATS) (four: Western and Eastern Europe, Asia), heroin (11: all settings), opiate-stimulants (four: North America, Western and Eastern Europe) and opiates-sedatives (five: Europe, Asia). HIV risk in cocaine injectors was 3.6 times 95% confidence interval (CI) = 2.8-4.7, I(2)  = 0%; n = 4) that of non-injectors and 3.0 for ATS injectors (95% CI = 2.2-4.1, I(2)  = 0%; n = 2). Higher sexual risk was reported in cohorts injecting stimulants. Compared to not-injecting, HIV IRR was 2.8 (95% CI = 1.7-4.7, I(2)  = 77%; n=6) for all heroin injectors and 3.5 (95% CI = 2.3-5.2, I(2)  = 40%; n=5) for heroin injectors in Asia and Europe., Conclusion: The risk of HIV acquisition in people who inject drugs appears to vary by drug type but differences are not statistically significant, precluding conclusive grading of risk., (© 2014 Society for the Study of Addiction.)

Aims: To investigate the impact of scaling-up opiate substitution therapy (OST) and high coverage needle and syringe programmes (100%NSP-obtaining more sterile syringes than you inject) on HCV prevalence among injecting drug users (IDUs)., Design: Hepatitis C virus HCV transmission modelling using U.K. estimates for effect of OST and 100%NSP on individual risk of HCV infection., Setting: Range of chronic HCV prevalent (20/40/60%) settings with no OST/100%NSP, and U.K. setting with 50% coverage of both OST and 100%NSP., Participants: Injecting drug users., Measurements: Decrease in HCV prevalence after 5-20 years due to scale-up of OST and 100%NSP to 20/40/60% coverage in no OST/100%NSP settings, or from 50% to 60/70/80% coverage in the U.K. setting., Findings: For 40% chronic HCV prevalence, scaling-up OST and 100%NSP from 0% to 20% coverage reduces HCV prevalence by 13% after 10 years. This increases to a 24/33% relative reduction at 40/60% coverage. Marginally less impact occurs in higher prevalence settings over 10 years, but this becomes more pronounced over time. In the United Kingdom, without current coverage levels of OST and 100%NSP the chronic HCV prevalence could be 65% instead of 40%. However, increasing OST and 100%NSP coverage further is unlikely to reduce chronic prevalence to less than 30% over 10 years unless coverage becomes ≥80%., Conclusions: Scaling-up opiate substitution therapy and high coverage needle and syringe programmes can reduce hepatitis C prevalence among injecting drug users, but reductions can be modest and require long-term sustained intervention coverage. In high coverage settings, other interventions are needed to further decrease hepatitis C prevalence. In low coverage settings, sustained scale-up of both interventions is needed., (© 2012 The Authors. Addiction © 2012 Society for the Study of Addiction.)

Aims: To investigate whether opiate substitution therapy (OST) and needle and syringe programmes (NSP) can reduce hepatitis C virus (HCV) transmission among injecting drug users (IDUs)., Design: Meta-analysis and pooled analysis, with logistic regression allowing adjustment for gender, injecting duration, crack injecting and homelessness., Setting: Six UK sites (Birmingham, Bristol, Glasgow, Leeds, London and Wales), community recruitment., Participants: A total of 2986 IDUs surveyed during 2001-09., Measurement: Questionnaire responses were used to define intervention categories for OST (on OST or not) and high NSP coverage (≥100% versus <100% needles per injection). The primary outcome was new HCV infection, measured as antibody seroconversion at follow-up or HCV antibody-negative/RNA-positive result in cross-sectional surveys., Findings: Preliminary meta-analysis showed little evidence of heterogeneity between the studies on the effects of OST (I2=48%, P=0.09) and NSP (I2=0%, P=0.75), allowing data pooling. The analysis of both interventions included 919 subjects with 40 new HCV infections. Both receiving OST and high NSP coverage were associated with a reduction in new HCV infection [adjusted odds ratios (AORs)=0.41, 95% confidence interval (CI): 0.21-0.82 and 0.48, 95% CI: 0.25-0.93, respectively]. Full harm reduction (on OST plus high NSP coverage) reduced the odds of new HCV infection by nearly 80% (AOR=0.21, 95% CI: 0.08-0.52). Full harm reduction was associated with a reduction in self-reported needle sharing by 48% (AOR 0.52, 95% CI: 0.32-0.83) and mean injecting frequency by 20.8 injections per month (95% CI: -27.3 to -14.4)., Conclusions: There is good evidence that uptake of opiate substitution therapy and high coverage of needle and syringe programmes can substantially reduce the risk of hepatitis C virus transmission among injecting drug users. Research is now required on whether the scaling-up of intervention exposure can reduce and limit hepatitis C virus prevalence in this population., (© 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.)

Background: Human immunodeficiency virus (HIV) outbreaks occur among injecting drug users (IDUs), but where HIV is low insight is required into the future risk of increased transmission. The relationship between hepatitis C virus (HCV) and HIV prevalence among IDUs is explored to determine whether HCV prevalence could indicate HIV risk., Methods: Systematic review of IDU HIV/HCV prevalence data and regression analysis using weighted prevalence estimates and time-series data., Results: HIV/HCV prevalence estimates were obtained for 343 regions. In regions other than South America/sub-Saharan Africa (SAm/SSA), mean IDU HIV prevalence is likely to be negligible if HCV prevalence is <30% (95% confidence interval 22-38%) but increases progressively with HCV prevalence thereafter [linearly (beta = 0.39 and R(2) = 0.67) or in proportion to cubed HCV prevalence (beta = 0.40 and R(2) = 0.67)]. In SAm/SSA, limited data suggest that mean HIV prevalence is proportional to HCV prevalence (beta = 0.84, R(2) = 0.99), but will be much greater than in non-SAm/SSA settings with no threshold HCV prevalence that corresponds to low HIV risk. At low HCV prevalences (<50%), time-series data suggest that any change in HIV prevalence over time is likely to be much smaller (<25%) than the change in HCV prevalence over the same time-period, but that this difference diminishes at higher HCV prevalences., Conclusions: HCV prevalence could be an indicator of HIV risk among IDUs. In most settings, reducing HCV prevalence below a threshold (30%) would reduce substantially any HIV risk, and could provide a target for HIV prevention.

Aims: To assess the cost-effectiveness of the CARE-SHAKTI harm reduction intervention for injecting drug users (IDUs) over a 3-year period, the impact on the cost-effectiveness of stopping after 3 years and how the cost-effectiveness might vary with baseline human immunodeficiency virus (HIV) prevalence., Design: Economic cost data were collected from the study site and combined with impact estimates derived from a dynamic mathematical model., Setting: Dhaka, Bangladesh, where the HIV prevalence has remained low despite high-risk sexual and injecting behaviours, and growing HIV epidemics in neighbouring countries., Findings: The cost per HIV infection prevented over the first 3 years was USD 110.4 (33.1-182.3). The incremental cost-effectiveness of continuing the intervention for a further year, relative to stopping at the end of year 3, is USD 97 if behaviour returns to pre-intervention patterns. When baseline IDU HIV prevalence is increased to 40%, the number of HIV infections averted is halved for the 3-year period and the cost per HIV infection prevented doubles to USD 228., Conclusions: The analysis confirms that harm reduction activities are cost-effective. Early intervention is more cost-effective than delaying activities, although this should not preclude later intervention. Starting harm reduction activities when IDU HIV prevalence reaches as high as 40% is still cost-effective. Continuing harm reduction activities once a project has matured is vital to sustaining its impact and cost-effectiveness.

Aims: To estimate long-term trends in cannabis use and projections of schizophrenia assuming a causal relation between cannabis use and schizophrenia., Methods: Trends in cannabis use were estimated from a national survey, 2003; and incidence of schizophrenia was derived from surveys in three English cities, 1997-99. A difference equation cohort model was fitted against estimates of schizophrenia incidence, trends in cannabis exposure and assumptions on association between cannabis and schizophrenia. The model projects trends in schizophrenia incidence, prevalence and attributable fraction of cannabis induced schizophrenia., Results: Between 1970 and 2002 cannabis exposure increased: incidence by fourfold; period prevalence by 10-fold; and use among under 18-year-olds by 18-fold. In 1997-99 incidence and prevalence of schizophrenia were 17 per 100 000 and 0.63% among men and 7.3 per 100 000 and 0.23% among women, respectively. If cannabis use causes schizophrenia, earlier increases in cannabis use would lead to increases in overall schizophrenia incidence and prevalence of 29% and 12% among men between 1990 and 2010. By 2010 model projections which assume an association between schizophrenia and light and heavy users suggest that approximately one-quarter of new schizophrenia cases could be due to cannabis, whereas if the association is twofold and confined to heavy cannabis users, then approximately 10% of schizophrenia cases may be due to cannabis., Conclusions: If cannabis use causes schizophrenia, and assuming other causes are unchanged, then relatively substantial increases in both prevalence and incidence of schizophrenia should be apparent by 2010. More accurate data on cannabis consumption and future monitoring of schizophrenia are critical.

Aim: To undertake a cost-effectiveness analysis of a harm reduction and HIV prevention project for injecting drug users (IDUs) in Eastern Europe. Economic evaluation methods were adapted to consider the effect of an 8-month financing gap that negatively impacted on project implementation., Design: Financial and economic costs of implementing the intervention were analysed retrospectively. The data were also modelled to estimate the costs of a fully functioning project. Estimates of the intervention impact on sexual and drug injecting behaviour were obtained from existing pre- and post-intervention behavioural surveys of IDUs. A dynamic mathematical model was used to translate these changes into estimates of HIV infections averted among IDUs and their sexual partners. Projections of the potential effect of the shortfall in funding on the impact and cost-effectiveness of the intervention were made., Setting: Svetlogorsk, Belarus, where in 1997 the IDU HIV prevalence was 74%., Findings: The intervention averted 176 HIV infections (95% CI 60-270) with a cost-effectiveness of 359 dollars per HIV infection averted (95% CI 234-1054 dollars). Without the 2311 dollars reduction (7%) in financing, the estimated cost-effectiveness ratio of the project would have been 11% lower. The costing methods used to measure donated mass media can substantially influence cost and cost-effectiveness estimates., Conclusions: Harm reduction activities among IDUs can be cost-effective, even when IDU HIV prevalence and incidence is high. Relatively small shortfalls in funding reduce impact and cost-effectiveness. Increased and consistent allocation of resources to harm reduction projects could significantly reduce the pace of the HIV epidemic in Eastern Europe.