HIV viral suppression (VS) is associated with individual and societal health and economic benefits. The HPTN 065 study found providing $70 financial incentives (FI) for VS to HIV patients in Bronx, NY, and Washington, DC, resulted in a significantly higher proportion of patients with VS (revised as 3.7%) at sites randomized to FI compared to standard care. We developed a mathematical model to evaluate the cost-effectiveness of FI in HPTN 065.
A two-part semi-Markov model was used to simulate the cohort of HIV patients in care at study sites and their sexual partners during the two-year intervention. The effect on VS was assumed to diminish to zero over six months when FIs end, with patients and partners followed over a lifetime horizon. The number of HIV transmissions during the study period was estimated with transmission risk equations. Study budgets and staff time informed cost parameters; self-reported sexual activity informed the number of partners; patient utility projection relied on literature-based utility by CD4 count. Lifetime total costs, HIV transmissions, and quality-adjusted life years (QALYs) are predicted from a health-care sector perspective and discounted 3% annually. We assumed a US willingness to pay of 3xGDP per capita threshold of $150,000/QALY for cost-effectiveness.
FIs for VS are likely to be highly cost-effective for HPTN 065 with an overall incremental cost-effectiveness ratio (ICER) of $7,371/QALY. Over two years, FI had a fixed cost of $167,714 per clinic for administration plus an average variable cost of $337 per patient for gift cards (Table 1). The resulting improvement in VS is projected to gain 19 patient QALYs and 20 partner QALYs in the population, and prevent 3 HIV infections for an average clinic with 456 patients on ART. Outpatient visits and ART costs increased 8.7% for FI patients; however, the estimated marginal increase in health care costs ($119 and $3,089 per patient respectively) are offset by savings from fewer HIV transmissions. A sensitivity analysis projected FI for VS cost-effective in all pre-specified sub-groups based on clinic size, type, baseline VS, and city with ICERs ranging from cost-saving to $79,471/QALY.
Financial incentives offer substantial value for money to improve the length and quality of life for HIV patients and their partners. This analysis provides evidence supporting the likely cost-effectiveness of an intervention to strengthen the clinical care continuum and reduce HIV transmission.