Introduction: Antiretroviral therapy (ART) cost is a barrier to ART adherence. In Melbourne, 2 pharmacies provide ART for the large majority of people living with HIV (PLHIV). The Melbourne Sexual Health Centre (MSHC) has no co-pay associated with ART pick-up, whereas the standard co-pay of $34.20 ($5.60 for Concession Card holders) applies at The Alfred hospital. For patients receiving HIV care close to the Alfred we determined the pharmacy of ART pick-up and ART adherence using pharmacy data.
Methods: The study population comprised patients picking up fixed dose combinations of: tenofovir-emtricitabine, abacavir-lamivudine or tenofovir-emtricitabine-efavirenz on ≥2 occasions from 2010-12. ART were prescribed by one of 8 general practitioners working at 1 high and 1 low caseload clinic near the Alfred. ART adherence was estimated using the medication possession ratio (MPR) calculated by dividing the days ART dispensed by the number of days from first to last pick-up. Median MPR at the 2 sites were compared by Wilcoxon Rank-Sum test and the relative risk for low adherence by site was established.
Results: 472 patients met inclusion criteria with 455/472 (96.4%) attended the high caseload clinic that is <1 kilometre from the Alfred and 5 kilometres from MSHC. 397/472 (84.1%) picked up from MSHC and 75/472 (15.9%) from the Alfred. Median (Q1-Q3) MPR was 99.2% (93.1%-102.6%) at MSHC and 97.9% (86.1%-102.5%) at the Alfred (p=0.12). There were increased risks for low adherence when picking up at the Alfred when defined as <95% adherence by MPR (RR 1.38; 95% CI 1.01-1.88, p=.05). Conclusion: The overwhelming majority of individuals pick-up ART at MSHC where there are no co-pays despite regular HIV care close to the Alfred. ART co-payment is associated with worse adherence as measured by the MPR. More detailed studies exploring associations between ART cost and adherence outcomes are warranted.
