Objective: Studies focusing on HIV-hepatitis C virus (HCV) coinfected individuals without a history of IDU are limited. It is plausible that poorer clinical outcomes in HIV-HCV coinfection are due to factors associated with IDU, not from HCV itself. This study compares HIV treatment outcomes and survival between HIV-HCV coinfected individuals with and without IDU history.
Design: Observational cohort study.
Methods: We analyzed data from a multisite Canadian cohort study of HIV-positive individuals initiating combination antiretroviral therapy (ART) after 1 January 2000. This analysis was restricted to 1254 participants with HCV coinfection and known IDU history. Cox proportional hazards regression was used to evaluate time from ART initiation to virologic suppression (two consecutive measures <250 copies/ml) and CD4+ cell count recovery (+100 cells/μl). In order to account for loss to follow-up (LTFU), competing risk analysis was used to evaluate time to death.
Results: A total of 1254 participants (31% women) were included. During a median follow-up time of 3.8 years (interquartile range = 2.1–6.2), 217 deaths were reported and 148 participants were LTFU. In adjusted multivariable analysis, individuals with IDU history were significantly less likely to achieve virologic suppression [adjusted hazard ratio (AHR) = 0.78, 95% confidence interval (CI) = 0.64–0.95]; marginally less likely to have CD4+ cell count recovery (AHR = 0.82, 95% CI = 0.66–1.00); and had a significantly higher risk of death (AHR = 2.15, 95% CI = 1.25–3.70).
Conclusion: IDU history independently elevates risk for poorer clinical outcomes, separate from HCV coinfection. HIV-HCV coinfected persons are not homogeneous in characteristics or outcomes, suggesting care should be taken during statistical analyses if attributing poorer HIV-specific outcomes solely to HCV coinfection.