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

Abstract

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.

Introduction

Among people who inject drugs (PWID), the median global hepatitis C virus (HCV) prevalence is estimated at 67% and is as high as 90% in certain settings (Nelson et al., 2011). In the United States, the number of HCV-related deaths between 2003–2013 has surpassed 60 other nationally notifiable infectious conditions combined (Ly, Hughes, Jiles, & Holmberg, 2016). It is widely acknowledged that timely engagement in HCV care, involving HCV testing and counselling, and assessment and treatment for those infected is key in reducing HCV-related morbidity and mortality (Grebely et al., 2015, World Health Organization, 2014).

More recently, research has attempted to investigate whether the benefits of HCV care may extend beyond liver-related outcomes (Alavi et al., 2015; Higgs, Wright, & Hellard, 2016; Younossi, Stepanova, Nader, Lam, & Hunt, 2015). Among PWID, there is some evidence to suggest that HCV treatment could have positive impacts on drug use behaviours. PWID engaged in treatment have access to regular monitoring and care, creating opportunities to receive counselling and discuss behaviour change (Aspinall et al., 2014, Bruneau et al., 2014, Spelman et al., 2015). Concurrent access to ancillary health care services and support, including primary care and addiction treatment may also play a role in influencing behaviour changes (Friedmann, Zhang, Hendrickson, Stein, & Gerstein, 2003; Nambiar, Agius, Stoove, Hickman, & Dietze, 2015; Saitz, Horton, Larson, Winter, & Samet, 2005). To date, only one study has specifically examined injection drug use changes in relation to HCV treatment exposure (Alavi et al., 2015). In this study of 124 PWID with acute or early chronic HCV followed for a median of 1.8 years in Australia, no association was found between treatment for HCV infection and past-month injection drug use (Alavi et al., 2015).

For decades, interferon-based therapy has been the standard of care for HCV. In light of the availability of new highly efficacious and well-tolerated therapies for HCV, recently shown to be associated with high cure rates among PWID (Dore et al., 2016), achieving an understanding of the impact of treatment on drug use behaviours in this population is particularly important in order to inform the ongoing debate on which patient groups to prioritize for treatment and related cost-benefit analyses (Scott, McBryde, Thompson, Doyle, & Hellard, 2016).

IMPACT was a longitudinal prospective cohort study in Montreal designed to investigate the effect of antiviral treatment on behaviour change in a community-based sample of current PWID with acute HCV, who were systematically referred for HCV clinical assessment and offered targeted health care services. The primary objective of this study was to compare eligible IMPACT participants who received treatment to those who chose not to engage in HCV care post-diagnosis with respect to their drug use changes over the course of a year. A subset of participating PWID were not eligible for treatment, either because they had spontaneously cleared the infection, or had contra-indications to therapy. As a secondary objective, we examined one-year injection drug use changes among these two groups and compared them with those who did not engage in HCV care.