The impact of drug coverage on viral suppression among people living with HIV in Ontario, Canada

Objectives We investigated the effect of drug coverage on viral suppression (sVL) in Ontario, Canada, where there is no universal coverage of prescription drugs, including anfiretroviral therapy (ART). Methods Ontarians without employment coverage may be eligible for varying degrees of coverage through government-sponsored programs. Remaining individuals pay all expenses entirely out of pocket. Among participants on ART enrolled in the Ontario HIV Treatment Network Cohort Study (OCS) who were interviewed in 2008-2013 with known or imputable drug coverage, we estimated the prevalence with sVL (<200 copies/mL) as of their last viral load each year. We calculated prevalence ratios (PR) according to time-updated socio-economic and behavioural factors using multivariable generalized estimating equations with a log-link function. Multiple imputation was used to assess the sensitivity of these findings to different assumed missing data models. Results One thousand two hundred forty-seven participants were included (3463 person-years). Compared to study participants with employer coverage, individuals covered through the Ontario Drug Benefit (ODB) were less likely to be suppressed (PR, 95% confidence interval (CI) 0.96, 0.93-0.98). After multivariable adjustment, ODB remained independently associated with less success in achieving sVL (adjusted PR, 95% CI 0.98, 0.95-0.99). These findings were robust to different assumptions about the missing data. Conclusion Our findings suggest that drug coverage can affect viral suppression in our setting. Further research is needed to identify the mechanisms by which coverage interacts with individual patient factors to affect viral suppression. Mechanisms to improve access and coverage for ART are needed.