Directly observed therapy programmes for anti-retroviral treatment amongst injection drug users in Vancouver: Access, adherence and outcomes

The introduction of highly active anti-retroviral therapy (HAART) has produced dramatic reductions in HIV associated morbidity and mortality. However, this success has not been replicated amongst injection drug users (IDUs) and other marginalised groups largely due to reduced uptake and lower rates of access and adherence to anti-retrovirals (ARVs). Multi-disciplinary programmes have been developed to help support ARV treatment and HIV care amongst IDUs. We retrospectively analysed the rates of adherence and plasma viral load suppression amongst participants in two clinic-based programmes that began enrollment in 1998. Of the 297 clients, the mean age was 40.5 years, 73% were males, 44% were of Aboriginal ethnicity, and 85% were Hepatitis C co-infected. One hundred and forty-two (47%) started therapy with a CD4 count below 200 mm−3, and baseline plasma viral load was over 100,000 copies/ml in 73 (25%). Treatment interruptions of greater than 2 weeks occurred in 41% of the participants during follow-up. The overall rate of adherence to treatment was 84.5% during periods when known interruptions were not considered. Plasma viral load suppression was attained by 29% during the first ARV regimen, although 83% had at least one fully suppressed plasma viral load recorded during follow-up. All cause mortality was 21% during the period of observation. The programmes initiated in Vancouver demonstrate the positive impact that a comprehensive DOT programme can have on ARV adherence, as well as highlight the challenges that remain.