Impact of hepatitis C virus point-of-care RNA viral load testing compared with laboratory-based testing on uptake of RNA testing and treatment, and turnaround times: a systematic review and meta-analysis.

BACKGROUND: Point-of-care (POC) hepatitis C virus (HCV) RNA nucleic acid test viral load assays are being used increasingly as an alternative to centralised, laboratory-based standard-of-care (SOC) viral load assays to reduce loss to follow-up. We aimed to evaluate the impact of using POC compared with SOC approaches on uptake of HCV RNA viral load testing and treatment, and turnaround times from testing to treatment along the HCV care cascade. METHODS: We searched PubMed, Embase, and Web of Science for studies published in English between Jan 1, 2016, and April 13, 2022. We additionally searched for accepted conference abstracts (2016-20) not identified in the main search. The contacts directory of the WHO Global Hepatitis Programme was also used to solicit additional studies on use of POC RNA assays. We included studies if they evaluated use of POC HCV RNA viral load with or without a comparator laboratory-based SOC assay, and had data on uptake of viral load testing and treatment, and turnaround times between these steps in cascade. We excluded studies with a sample size of ten or fewer participants. The POC studies were categorised according to whether the POC assay was based onsite at the clinic, in a mobile unit, or in a laboratory. Studies using the POC assay or comparator SOC assays were further stratified according to four models of care: whether HCV testing and treatment initiation were performed in the same or different site, and on the same or a different visit. The comparator was centralised, laboratory-based HCV RNA SOC assays. For turnaround times, we calculated the weighted median of medians with 95% CIs. We analysed viral load testing and treatment uptake using random-effects meta-analysis. The quality of evidence was rated using the GRADE framework. This study is registered with PROSPERO, CRD42020218239. FINDINGS: We included 45 studies with 64 within-study arms: 28 studies were in people who inject drugs, were homeless, or both; four were in people incarcerated in prison; nine were in the general or mixed (ie, includes high-risk groups) populations; and four were in people living with HIV. All were observational studies. The pooled median turnaround times between HCV antibody test and treatment initiation was shorter with onsite POC assays (19 days [95% CI 14-53], ten arms) than with either laboratory-based POC assays (64 days [64-64], one arm) or laboratory-based SOC assays (67 days [50-67], two arms). Treatment uptake was higher with onsite POC assays (77% [95% CI 72-83], 34 arms) or mobile POC assays (81% [60-97], five arms) than with SOC assays (53% [31-75], 12 arms); onsite and mobile POC assay vs SOC assay p=0·029). For POC and SOC arms, higher RNA viral load testing uptake was seen with the same-site models for testing and treatment than with different-site models (all within-category p≤0·0001). For onsite and mobile POC arms, there was higher treatment uptake for same-site than different-site models (within-category p<0·0001). Four studies had direct within-study POC versus SOC comparisons for RNA viral load testing uptake (pooled relative risk 1·11 [95% CI 0·89-1·38]), and there were ten studies on treatment uptake (1·32 [1·06-1·64]). Overall, the quality of evidence was rated as low. INTERPRETATION: Compared with use of laboratory-based SOC HCV viral load testing, the use of POC assays was associated with reduced time from antibody test to treatment initiation and increased treatment uptake. The effect of POC viral load testing is greatest when positioned within a simplified care model in which testing and treatment are provided at the same site, and, where possible, on the same day. POC HCV RNA viral load testing is now recommended in WHO guidelines as an alternative strategy to laboratory-based viral load testing. FUNDING: Unitaid.

Injecting frequency trajectories and hepatitis C virus acquisition: Findings from a cohort of people who inject drugs in Montréal, Canada.

BACKGROUND: Frequent injecting increases hepatitis C (HCV) acquisition risk among people who inject drugs (PWID). However, few studies have examined how temporal fluctuations in injecting frequency may effect HCV infection risk. Thus, this study examined HCV incidence according to injecting frequency trajectories followed by PWID over one year in Montréal, Canada. METHODS: At three-month intervals from March 2011 to June 2016, HCV-uninfected PWID (never infected or cleared infection) enrolled in the Hepatitis Cohort (HEPCO) completed interviewer-administered questionnaires and HCV testing. At each visit, participants reported the number of injecting days (0-30 days) for each of the past three months. In previous work, using group-based trajectory modeling, we identified five injecting frequency trajectories followed by participants over one year (months 1-12 of follow-up), including sporadic, infrequent, increasing, decreasing, and frequent injecting. In this study, we estimated group-specific HCV incidence (months 1-63 of follow-up) using posterior probabilities to assign participants to their most likely trajectory group. RESULTS: Of 386 participants (mean age=40, 82% male, 48% never HCV-infected), 72 acquired HCV during 893 person-years of follow-up. HCV incidence for the whole study sample was 8.1 per 100 person-years (95%CI=6.4-10.1). Trajectory group-specific HCV incidences were highest for those injecting drugs with decreasing (23.9, 14.4-37.5) or increasing frequency (16.0, 10.1-24.3), intermediate for those injecting at consistently high frequency (10.2, 5.4-17.8), and lowest for those injecting infrequently (3.9, 2.2-6.5) or sporadically (4.3, 2.2-7.6). CONCLUSION: Results suggest that PWID at highest HCV risk are those injecting at high frequency, either transitorily (increasing, decreasing injecting) or consistently (frequent injecting). This study highlights changes in injecting frequency as a potentially important dimension to consider among the factors leading to HCV acquisition. Clinical and public health interventions tailored to PWID with different injecting frequency profiles may contribute to HCV prevention.

Diversity of incarceration patterns among people who inject drugs and the association with incident hepatitis C virus infection.

BACKGROUND: Little is known about the relationship between short-term incarceration and risk of hepatitis C virus (HCV) infection among people who inject drugs (PWID). We investigated whether varying patterns of recent incarceration lasting less than two years are associated with HCV acquisition risk in this population. METHODS: We followed prospectively PWID at risk of acquiring HCV infection in Montréal (2004-2019). At 6-month (up until 2011), then 3-month intervals, participants were tested for HCV antibodies or RNA, and self-reported whether they have been incarcerated in each of the previous 6 or 3 months. If incarcerated, they reported the setting and time spent in incarceration. We fit three separate multivariable time-updated Cox regression models, one for each measure of incarceration: any incarceration lasting less than two years (yes/no), incarceration stratified by setting (local police station/provincial prison/no) and incarceration stratified by time in incarceration (≤1 week/>1 week and ≤1 month/>1 month and <2 years/no). RESULTS: Among 709 PWID followed over 2315.2 person-years, HCV incidence was 9.9/100 person-years (95% confidence interval (CI): 8.7-11.2)]. During follow-up, 248 PWID (35.0%) reported at least one recent incarceration episode of less than two years. Overall, compared to PWID who did not experience incarceration in the prior 6 or 3 months, PWID who did were 1.56 (95% CI: 1.13, 2.17) times more likely to acquire HCV. We found no statistically significant difference in the magnitude of associations across categories of setting and time in incarceration (likelihood ratio test P= 0.53 and 0.44, respectively). CONCLUSION: Any recent incarceration lasting less than two years, regardless of the setting and time in incarceration, was associated with an elevated risk of HCV acquisition among PWID. Findings support the need to expand access to harm-reduction programs in short-term incarceration settings and, in parallel, to prioritise public health-oriented alternatives to incarcerating PWID where possible.

Socioeconomic stability is associated with lower injection frequency among people with distinct trajectories of injection drug use.

BACKGROUND: Little is known about how socioeconomic circumstances relate to injection frequencies among people who inject drugs (PWID) with diverse trajectories of injection. We aimed to characterize trajectories of injection drug use in a community-based sample of PWID over 7.5 years and to investigate the extent to which two modifiable factors reflecting socioeconomic stability-stable housing and stable income-relate to injection frequencies across distinct trajectories. METHODS: HEPCO is an open, prospective cohort study of PWID living in Montréal with repeated follow-up at three-month or one-year intervals. Self-reported data on injection frequency, housing and income are collected at each visit. Injection frequency was defined as the number of injection days (0-30), reported for each of the past three months. Using group-based trajectory modeling, we first estimated average trajectories of injection frequency. Then, we estimated the trajectory group-specific average shift upward or downward associated with periods of stable housing and stable income relative to periods when these conditions were unstable. RESULTS: Based on 19,527 injection frequency observations accrued by 529 participants followed over 2011-2019 (18.3% female, median age: 41), we identified five trajectories of injection frequency: three characterized by sustained injection at different frequencies (28% infrequent; 19% fluctuating; 19% frequent), one by a gradual decline (12%), and another by cessation (28%). Periods of stable housing and stable income were each independently associated with a lower injection frequency, on average, in all five trajectory groups (2.2-7.5 fewer injection days/month, depending on the factor and trajectory group). CONCLUSION: Trajectories of injection drug use frequency were diverse and long-lasting for many PWID. Despite this diversity, socioeconomic stability was consistently associated with a lower injection frequency, emphasizing the close relationship between access to fundamental necessities and injection patterns in all PWID, irrespective of whether they are on a path to cessation or sustained injecting.

Homelessness, unstable housing, and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis.

BACKGROUND: People who inject drugs (PWID) are at increased risk for HIV and hepatitis C virus (HCV) infection and also have high levels of homelessness and unstable housing. We assessed whether homelessness or unstable housing is associated with an increased risk of HIV or HCV acquisition among PWID compared with PWID who are not homeless or are stably housed. METHODS: In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies published between Jan 1, 2000, and June 13, 2017. Using the same strategy as for this existing database, we searched MEDLINE, Embase, and PsycINFO for studies, including conference abstracts, published between June 13, 2017, and Sept 14, 2020, that estimated HIV or HCV incidence, or both, among community-recruited PWID. We only included studies reporting original results without restrictions to study design or language. We contacted authors of studies that reported HIV or HCV incidence, or both, but did not report on an association with homelessness or unstable housing, to request crude data and, where possible, adjusted effect estimates. We extracted effect estimates and pooled data using random-effects meta-analyses to quantify the associations between recent (current or within the past year) homelessness or unstable housing compared with not recent homelessness or unstable housing, and risk of HIV or HCV acquisition. We assessed risk of bias using the Newcastle-Ottawa Scale and between-study heterogeneity using the I2 statistic and p value for heterogeneity. FINDINGS: We identified 14 351 references in our database search, of which 392 were subjected to full-text review alongside 277 studies from our existing database. Of these studies, 55 studies met inclusion criteria. We contacted the authors of 227 studies that reported HIV or HCV incidence in PWID but did not report association with the exposure of interest and obtained 48 unpublished estimates from 21 studies. After removal of duplicate data, we included 37 studies with 70 estimates (26 for HIV; 44 for HCV). Studies originated from 16 countries including in North America, Europe, Australia, east Africa, and Asia. Pooling unadjusted estimates, recent homelessness or unstable housing was associated with an increased risk of acquiring HIV (crude relative risk [cRR] 1·55 [95% CI 1·23-1·95; p=0·0002]; I2= 62·7%; n=17) and HCV (1·65 [1·44-1·90; p<0·0001]; I2= 44·8%; n=28]) among PWID compared with those who were not homeless or were stably housed. Associations for both HIV and HCV persisted when pooling adjusted estimates (adjusted relative risk for HIV: 1·39 [95% CI 1·06-1·84; p=0·019]; I2= 65·5%; n=9; and for HCV: 1·64 [1·43-1·89; p<0·0001]; I2= 9·6%; n=14). For risk of HIV acquisition, the association for unstable housing (cRR 1·82 [1·13-2·95; p=0·014]; n=5) was higher than for homelessness (1·44 [1·13-1·83; p=0·0036]; n=12), whereas no difference was seen between these outcomes for risk of HCV acquisition (1·72 [1·48-1·99; p<0·0001] for unstable housing, 1·66 [1·37-2·00; p<0·0001] for homelessness). INTERPRETATION: Homelessness and unstable housing are associated with increased risk of HIV and HCV acquisition among PWID. Our findings support the development of interventions that simultaneously address homelessness and unstable housing and HIV and HCV transmission in this population. FUNDING: National Institute for Health Research, National Institute on Drug Abuse, National Institute of Allergy and Infectious Diseases, and Commonwealth Scholarship Commission.

Associations between housing stability and injecting frequency fluctuations: findings from a cohort of people who inject drugs in Montréal, Canada.

BACKGROUND: The relationship between housing stability and drug injecting is complex, as both outcomes fluctuate over time. The objectives were to identify short-term trajectories of housing stability and injecting frequency among people who inject drugs (PWID) and examine how patterns of injecting frequency relate to those of housing stability. METHODS: At three-month intervals, PWID enrolled between 2011 and 2016 in the Hepatitis Cohort completed an interviewer-administered questionnaire and were tested for hepatitis C and HIV infections. At each visit, participants reported, for each of the past three months, the accommodation they lived in the longest (stable/unstable) and the number of injecting days (0-30). Group-based dual trajectory modeling was conducted to identify housing stability and injecting frequency trajectories evolving concomitantly over 12 months and estimate the probabilities of following injecting trajectories conditional upon housing trajectories. RESULTS: 386 participants were included (mean age 40.0, 82 % male). Three housing stability trajectories were identified: sustained (53 %), declining (20 %), and improving (27 %). Five injecting frequency trajectories were identified: sporadic (26 %), infrequent (34 %), increasing (15 %), decreasing (11 %), and frequent (13 %). PWID with improving housing were less likely to increase injecting (8 %) compared to those with sustained (17 %) or declining housing (17 %). CONCLUSIONS: Improving housing was associated with a lower probability of increasing injecting compared to declining housing, while sustained housing stability was associated with a higher probability of increasing injecting compared to improving housing. Therefore, policies to improve PWID's access to stable housing are warranted and may reduce, to some extent, drug injecting and related harms.

Sexual behaviour as a risk factor for hepatitis C virus infection among people who inject drugs in Montreal, Canada.

Hepatitis C virus (HCV) acquisition remains high in key risk environments including injection drug use and sex between men. However, few studies examine the independent contribution of sexual behaviour to HCV acquisition among people who inject drugs (PWID). We estimated HCV incidence and examined sexual behaviour as a time-varying predictor of HCV acquisition in a prospective cohort study of PWID in Montreal (2004-2017). Initially, HCV-negative participants completed behavioural questionnaires and HCV antibody testing (6 months until 2011, 3 months thereafter). A time-updating exposure variable (no sex, opposite-sex partner only, ≥1 same-sex partner) was generated for the previous 6/3 months. Time to HCV seroconversion was examined using Cox regression analysis, adjusted for age, unstable housing and incarceration (both past 3 months), and daily, heroin, cocaine and prescription opioid injecting (all past month). Among 440 PWID (baseline: median age 33 years, 18.9% female, 1.4% HIV-positive), 156 participants seroconverted during follow-up (overall incidence rate: 11.9/100 person-years [PY]). Incidence was lowest in the no sex group (8.70 and 2.91 cases/100 PY in males and females, respectively) and highest in the ≥1 same-sex partner group (24.14 and 21.97 cases/100 PY in males and females, respectively). Among males, HCV risk was 47% lower in those reporting no sex compared to ≥1 same-sex partner (adjusted hazard ratio: 0.53, 95% confidence interval: 0.28, 0.99). In this cohort of PWID, reporting recent same-sex partners was associated with greater risk of HCV acquisition among males, necessitating targeted harm reduction strategies that consider the complex interplay of sexual and injecting risk behaviours.

Short and sporadic injecting cessation episodes as predictors of incident hepatitis C virus infection: findings from a cohort study of people who inject drugs in Montréal, Canada.

BACKGROUND AND AIMS: For most people who inject drugs (PWID), drug injecting follows a dynamic process characterized by transitions in and out of injecting. The objective of this investigation was to examine injecting cessation episodes of 1-3-month duration as predictors of hepatitis C virus (HCV) acquisition. DESIGN: Cohort study. SETTING: Montréal, Canada. PARTICIPANTS: A total of 372 HCV-uninfected (HCV RNA-negative, HCV antibody-positive or -negative) PWID (mean age = 39.3 years, 82% male, 45% HCV antibody-positive) enrolled between March 2011 and June 2016. MEASUREMENTS: At 3-month intervals, participants completed an interviewer-administered questionnaire and were tested for HCV particles (HCV RNA). At each visit, participants indicated whether they injected in each of the past 3 months (defined as three consecutive 30-day periods). Injecting cessation patterns were evaluated on a categorical scale: persistent injecting (no injecting cessation in the past 3 months), sporadic injecting cessation (injecting cessation in 1 of 3 or 2 of 3 months) and short injecting cessation (injecting cessation in 3 of 3 months). Their association with HCV infection risk was examined using Cox regression analyses with time-dependent covariates, including age, gender, incarceration, opioid agonist treatment and other addiction treatments. FINDINGS: At baseline, 61, 26 and 13% of participants reported persistent injecting, sporadic injecting cessation and short injecting cessation, respectively. HCV incidence was 7.5 per 100 person-years [95% confidence interval (CI) = 5.9-9.5; 916 person-years of follow-up]. In adjusted Cox models, sporadic injecting cessation and short injecting cessation were associated with lower risks of incident HCV infection compared to persistent injecting (adjusted hazard ratios = 0.56, 95% CI = 0.30-1.04 and 0.24, 95% CI = 0.09-0.61), respectively. CONCLUSION: Short and sporadic injecting cessation episodes were common among a cohort of people who inject drugs in Montréal, Canada. Injecting cessation episodes appear to be protective against hepatitis C virus acquisition, particularly when maintained for at least 3 months.

Conceptualising access in the direct-acting antiviral era: An integrated framework to inform research and practice in HCV care for people who inject drugs.

As direct-acting antiviral (DAA) therapy costs fall and eligibility criteria are relaxed, people who inject drugs (PWID) will increasingly become eligible for HCV treatment. Yet eligibility does not necessarily equate to access. Amidst efforts to expand treatment uptake in this population, we seek to synthesise and clarify the conceptual underpinnings of access to health care for PWID, with a view to informing research and practice. Integrating dominant frameworks of health service utilisation, care seeking processes, and ecological perspectives on health promotion, we present a comprehensive theoretical framework to understand, investigate and intervene upon barriers and facilitators to HCV care for PWID. Built upon the concept of Candidacy, the framework describes access to care as a continually negotiated product of the alignment between individuals, health professionals, and health systems. Individuals must identify themselves as candidates for services and then work to stake this claim; health professionals serve as gatekeepers, adjudicating asserted candidacies within the context of localised operating conditions; and repeated interactions build experiential knowledge and patient-practitioner relationships, influencing identification and assertion of candidacy over time. These processes occur within a complex social ecology of interdependent individual, service, system, and policy factors, on which other established theories provide guidance. There is a pressing need for a deliberate and nuanced theory of health care access to complement efforts to document the HCV 'cascade of care' among PWID. We offer this framework as an organising device for observational research, intervention, and implementation science to expand access to HCV care in this vulnerable population. Using practical examples from the HCV literature, we demonstrate its utility for specifying research questions and intervention targets across multiple levels of influence; describing and testing plausible effect mechanisms; and identifying potential threats to validity or barriers to research translation.

The role of prevention strategies in achieving HCV elimination in Canada: what are the remaining challenges?

Background: The worldwide economic, health, and social consequences of drug use disorders are devastating. Injection drug use is now a major factor contributing to hepatitis C virus (HCV) transmission globally, and it is an important public health concern. Methods: This article presents a narrative review of scientific evidence on public health strategies for HCV prevention among people who inject drugs (PWID) in Canada. Results: A combination of public health strategies including timely HCV detection and harm reduction (mostly needle and syringe programmes and opioid substitution therapy) have helped to reduce HCV transmission among PWID. The rising prevalence of pharmaceutical opioid and methamphetamine use and associated HCV risk in several Canadian settings has prompted further innovation in harm reduction, including supervised injection facilities and low-threshold opioid substitution therapies. Further significant decreases in HCV incidence and prevalence, and in corresponding disease burden, can only be accomplished by reducing transmission among high-risk persons and enhancing access to HCV treatment for those at the greatest risk of disease progression or viral transmission. Highly effective and tolerable direct-acting antiviral therapies have transformed the landscape for HCV-infected patients and are a valuable addition to the prevention toolkit. Curing HCV-infected persons, and thus eliminating new infections, is now a real possibility. Conclusions: Prevention strategies have not yet ended HCV transmission, and sharing of injecting equipment among PWID continues to challenge the World Health Organization goal of eliminating HCV as a global public health threat by 2030. Future needs for research, intervention implementation, and uptake in Canada are discussed.

Neurostimulation for Refractory Cervicogenic Headache: A Three-Year Retrospective Study.

BACKGROUND: Occipital nerve stimulation (ONS) has been used for the treatment of neuropathic pain conditions and could be a therapeutic approach for refractory cervicogenic headache (CeH). AIM: The aim of this study is to assess the efficacy and safety of unilateral ONS in patients suffering from refractory CeH. METHODS: We conducted a retrospective chart review on patients implanted from 2011 to 2013 at CHUM. The primary outcome was a 50% reduction in headache days per month. Secondary outcomes included change in EuroQol Group Visual Analog Scale rating of health-related quality of life (EQ VAS), six item headache impact test (HIT-6) score, hospital anxiety and depression scale (HADS) score, work status, and medication overuse. RESULTS: Sixteen patients fulfilled the inclusion criteria; they had suffered from daily moderate to severe CeH for a median of 15 years. At one year follow-up, 11 patients were responders (69%). There was a statistically significant improvement in the EQ VAS score (median change: 40 point increase, p = 0.0013) and HIT-6 score (median change: 17.5 point decrease, p = 0.0005). Clinically significant anxiety and depression scores both resolved amongst 60% of patients. At three years, six patients were responders (37.5%). Out of the 11 responders at one-year post implantation, five had remained headache responders (R-R) and one additional patient became a responder (NR-R). There was a statistically significant improvement in the EQ VAS score (median change: 15 point increase, p = 0.019) and HIT-6 score (median change: 7.5 point decrease, p = 0.0017) compared with baseline. Clinically significant anxiety and depression scores both, respectively, resolved among 22.5% and 33.9% of patients. Five out of seven disabled patients were back to work. CONCLUSION: ONS may be a safe and effective treatment modality for patients suffering from a refractory CeH. Further study may be warranted.

High hepatitis C incidence in relation to prescription opioid injection and poly-drug use: Assessing barriers to hepatitis C prevention.

BACKGROUND: Prescription opioid (PO) injection and poly-drug use have been associated with hepatitis C virus (HCV) infection among people who inject drugs (PWID). Poly-drug use is often a barrier to key HCV preventive programmes including opioid agonist treatment. The contribution of specific drug combinations to high HCV incidence in poly-drug users has not been assessed previously. Addressing this knowledge gap could enhance HCV treatment and prevention efforts. We examined the association between specific drugs and number of drugs used in addition to injected POs, and HCV seroconversion. METHODS: PWID participating in a cohort study in Montréal (HEPCO), HCV-seronegative at baseline and followed between 2004 and 2013, were included. Data were collected by interview-administered questionnaires. Blood samples were tested for HCV new infections at each 3-6 month follow-up visit. Time-varying Cox regression models were utilized. RESULTS: Of 356 participants (81.5% males; mean age: 34.7 years), 123 (34.6%) reported injected POs in the past month at baseline. In univariate analyses, recent use of the following drugs was associated with HCV seroconversion: injected POs, injected cocaine, injected heroin, non-injected tranquilisers, and smoked crack/cocaine. The relative excess risk of HCV seroconversion due to interaction (RER1HR) was the highest for co-use of injected POs with the following substances: injected cocaine (RER1HR=3.44), smoked crack/cocaine (RER1HR=1.27), and non-injected tranquilisers (RER1HR=0.8). In addition, a significant linear trend (p<0.001) towards higher risk was observed with increasing the number of these three drugs used in combination with injected POs. CONCLUSION: Specific drugs and number of drugs used in addition to injected POs play a modulating role in the risk of HCV primary infection. Poly-drug use among people who inject POs has to be addressed in order to improve harm reduction programmes and reduce HCV transmission in this high-risk population.

Short-term injection drug use changes following hepatitis C virus (HCV) assessment and treatment among persons who inject drugs with acute HCV infection.

BACKGROUND: It is unclear whether treatment and care for hepatitis C virus (HCV) infection can help people who inject drugs (PWID) modify their injection drug use behaviours. This study examined changes in injection drug use among PWID with acute HCV systematically referred for HCV clinical assessment and treatment and offered targeted health care services, over the course of one year. METHODS: The study sample included PWID with documented acute HCV infection recruited and followed-up semi-annually at least twice in IMPACT (2007-2015), a longitudinal community-based prospective study in Montréal, Canada. Following enrolment, participants with contra-indications to treatment due to severe co-morbidity were offered targeted health care services. Pegylated interferon-alpha (12-24 weeks) was offered to all other participants who did not spontaneously resolve their infection. At each study visit, data were collected on socio-demographic factors and drug use patterns. Logistic regression was used to assess changes in injection drug use at one-year follow-up. RESULTS: Of the 87 eligible participants (mean age: 35.6; 78.2% male), 21.8% received treatment [(RT), Sustained virological response: 84.2%], 25.3% spontaneously resolved their infection (SR), 14.9% had contra-indication(s) (CI) and 37.9% chose not to engage in HCV care post-diagnosis (NE). In multivariate analyses adjusting for age, gender and injection drug use at baseline, the RT [Adjusted odds ratio (AOR): 0.18; 95% Confidence interval (CI): 0.04-0.76], SR (AOR: 0.34; 95% CI: 0.08-1.40), and CI (AOR: 0.24; 95% CI: 0.05-1.22) groups were less likely to report injection drug use at follow-up relative to the NE group. CONCLUSION: PWID who received treatment, spontaneously resolved their infection or presented with treatment contra-indication(s) reported reduced injection drug use at one-year follow-up relative to those who did not engage in therapy. Findings suggest that the benefits of HCV assessment and treatment may extent to helping PWID modify their injection drug use patterns.

Examining the link between psychological distress, mental health disorders and sharing behaviors among cocaine users.

BACKGROUND: Psychiatric problems and cocaine use are associated with heightened vulnerability for HIV and Hepatitis C infections. Little is known regarding the relationship between psychiatric symptoms, psychiatric diagnoses and injection risk behaviors among cocaine users. We examined the association between psychological distress and injection material sharing among cocaine users, while accounting for comorbid anxious and mood disorders. METHODS: Participants included cocaine users who inject drugs recruited in a prospective cohort study in Montreal, Canada. Diagnosis of mood and anxiety disorders in the year preceding baseline were established using the Composite International Diagnostic Interview (CIDI) questionnaire. Psychological distress based on the Kessler scale and injection material sharing in the past 3months were assessed at baseline and at each of the five follow-up visits at 3-month intervals. Statistical analyses were conducted using generalized estimation equation. RESULTS: Of the 387 participants (84.5% male; 80.1%, ≥30y.o.), 35% reported severe psychological distress, 43% qualified for an anxiety disorder diagnosis and 29% for a mood disorder diagnosis at baseline. Psychological distress was not associated with any injection risk behavior when adjusting for socio-demographic and psychiatric disorders. Participants with anxiety disorders were more likely to share needle (adjusted odds ratio: 1.89, 95% CI: 1.17-3.03). Sharing of injection material other than needle was not associated with psychiatric disorders or with psychological distress in multivariate analyses. CONCLUSIONS: Anxiety disorders are associated with needle sharing among cocaine users. Our results suggest the importance of screening for anxiety disorders as part of preventive interventions to decrease blood-borne viruses' transmission.

Licit and illicit substance use among people who inject drugs and the association with subsequent suicidal attempt.

AIM: To estimate associations between recent licit and illicit substance use and subsequent suicide attempt among people who inject drugs (PWID). DESIGN: Secondary analysis of longitudinal data from a prospective cohort study of PWID followed bi-annually between 2004 and 2011. SETTING: Montréal, Canada. PARTICIPANTS: Seven hundred and ninety-seven PWID who reported injection drug use in the previous 6 months, contributing to a total of 4460 study visits. The median number of visits per participant was five (interquartile range: 3-8). MEASUREMENTS: An interviewer-administered questionnaire eliciting information on socio-demographic factors, detailed information on substance use patterns and related behaviours, mental health markers and suicide attempt. The primary exposure variables examined were past-month use of alcohol [heavy (≥ 60 drinks); moderate (one to 59 drinks); none], sedative-hypnotics, cannabis, cocaine, amphetamine and opioids [regular (≥ 4 days); occasional (1-3 days); none]. The outcome was a binary measure of suicide attempt assessed in reference to the previous 6 months. FINDINGS: In multivariate analyses, a positive association was found among licit substances between heavy alcohol consumption [adjusted odds ratio (AOR) = 2.05; 95% confidence interval (CI) = 1.12-3.75], regular use of sedative-hypnotics (AOR = 1.89; 95% CI = 1.21-2.95) and subsequent attempted suicide. Among illicit substances, occasional use of cannabis (AOR = 1.84; 95% CI = 1.09-3.13) had a positive association with subsequent suicide attempt. No statistically significant association was found for the remaining substances. CONCLUSION: Among people who inject drugs, use of alcohol, sedative-hypnotics and cannabis, but not cocaine, amphetamine or opioids, appears to be associated with an increased likelihood of later attempted suicide.

Hepatitis C Virus seroconversion among persons who inject drugs in relation to primary care physician visiting: The potential role of primary healthcare in a combined approach to Hepatitis C prevention.

BACKGROUND: Meaningful reductions in Hepatitis C Virus (HCV) transmission rates among persons who inject drugs (PWID) require a comprehensive prevention approach, including access to harm reduction measures and to healthcare-related interventions, such as HCV screening, testing and antiviral treatment. Little is known, however, about the role of visiting a primary care physician (PCP) in relation to HCV infection risk among PWID, when integrated within a combined prevention approach. This study assessed the association between PCP visiting and HCV seroconversion among PWID attending needle exchange programs (NEP). METHODS: A prospective cohort study, HEPCO, was conducted among active PWID in Montréal (2004-2013). Interviews scheduled at 3- or 6-month intervals included completion of an interviewer-administered questionnaire, and collection of blood samples for HCV antibody testing. HCV-seronegative participants who reported NEP attendance at baseline and had at least one follow-up visit were eligible for this study. HCV incidence was calculated using the person-time method. Time-varying Cox regression modeling was conducted to evaluate the relationship between self-reported recent PCP visiting and HCV incidence. RESULTS: At baseline assessment, of 226 participants (80.5% male; median age: 30.6 years), 37.2% reported having recently visited a PCP. During 449.6 person-years of follow-up, 79 participants seroconverted to HCV [incidence rate: 17.6 per 100 person-years, 95% confidence interval (CI): 14.0-21.8]. Covariate-adjusted analyses indicated that visiting a PCP was associated with a lower risk of HCV infection [Adjusted Hazard Ratio: 0.54, 95% CI: 0.31-0.93]. Other independent predictors of HCV infection included unstable housing, cocaine injection and prescription opioid injection. CONCLUSION: Among PWID attending NEP, visiting a PCP was associated with a lower risk of HCV infection. Yet, only a minority of participants reported PCP visiting. Efforts to intensify engagement with PCP among PWID could potentially contribute to lower HCV transmission when integrated within a combined approach to prevention.

Associations of substance use patterns with attempted suicide among persons who inject drugs: can distinct use patterns play a role?

BACKGROUND: While the elevated risk of suicide attempt among persons who inject drugs (PWID) is well documented, whether use of different substances is associated with varying degrees of risk remains unclear. We sought to examine the associations between substance use patterns and attempted suicide in a prospective cohort of PWID in Montreal, Canada. METHODS: Between 2004 and 2011, participants completed an interviewer-administered questionnaire eliciting information on socio-demographics, substance use patterns, related behaviors, and mental health markers. Generalized estimating equations were used to model the relationship between self-reported use of six common substances (cocaine, amphetamine, opioids, sedative-hypnotics, cannabis and alcohol), associated patterns of use (chronic, occasional and none), and a recent (past six-month) suicide attempt. RESULTS: At baseline, of 1240 participants (median age: 39.1, 83.7% male), 71 (5.7%) reported a recent suicide attempt. Among 5621 observations collected during follow-up, 221 attempts were reported by 143 (11.5%) participants. In multivariate analyses adjusting for socio-demographics and psychosocial stressors, among primary drugs of abuse, chronic [adjusted odds ratio (AOR): 1.97] and occasional (AOR: 1.92) cocaine use, and chronic amphetamine use (AOR: 1.96) were independently associated with attempted suicide. Among co-used substances, chronic sedative-hypnotic use was independently associated with an attempt (AOR: 2.29). No statistically significant association was found for the remaining substances. CONCLUSION: Among PWID at high risk of attempted suicide, stimulant users appear to constitute a particularly vulnerable sub-group. While the mechanisms underlying these associations remain to be elucidated, findings suggest that stimulant-using PWID should constitute a prime focus of suicide prevention efforts.