Impact of the removal of patient co-payments for antiretroviral therapy (ART) on out-of-pocket expenditure, adherence and virological failure among Australian adults living with HIV

Background:: In 2015, New South Wales (Australia) removed patient co-payments for ART of HIV. We hypothesized the policy change would reduce overall out-of-pocket (OOP) healthcare expenditure, improve ART adherence, and better maintain HIV suppression. Methods: Using data from a national, 2-year prospective study of adults with HIV on ART (n=364) (2013-2017), we compared OOP healthcare expenditure, ART adherence, and virological failure (VF) in participants subject to the co-payment policy change with participants from other jurisdictions who never paid, and who always paid, co-payments. We used fixed effects regression models to compare outcomes, and incidence rates for VF. Results:: Although ART co-payments declined, there was no significant change in total OOP healthcare expenditure in participants ceasing co-payments compared to those who continued (adjusted coefficient 0.09, 95% CI -0.31 to 0.48). Co-payment removal did not significantly reduce suboptimal ART adherence (from 17.5% to 16.3%) or VF (from 5.0 to 3.7 episodes per-100-person-years). Participants in the lowest income group but not receiving concessional government benefits incurred a non-significant increase in total OOP healthcare expenses; while concessional participants experienced a significant increase in non-ART HIV healthcare costs after the policy changed. Conclusion:: In this population, ART co-payments represented a small proportion of OOP healthcare expenditure. Its removal did not materially impact ART adherence or VF, although the study was not powered to detect these.