Behavioral economic incentives to support HIV care: Results from a randomized controlled trial in Uganda

Abstract

Background: This study tests behavioral economics incentives to improve adherence to antiretroviral treatment (ART), with one approach being low-cost. Setting: 329 adults at Mildmay Hospital in Kampala, Uganda on ART for at least two years and showing adherence problems received the intervention for about 15 months until the study was interrupted by a nation-wide COVID-19 lockdown. Methods: We randomized participants into one of three (1:1:1) groups: usual care (‘control’ group; n=109) or one of two intervention groups where eligibility for non-monetary prizes was based on: showing at least 90% electronically measured ART adherence (‘adherence-linked’ group, n=111); or keeping clinic appointments as scheduled (‘clinic-linked’; n=109). After 12 months, participants could win a larger prize for consistently high adherence or viral suppression. Primary outcomes were mean adherence and viral suppression. Analysis was by intention-to-treat using linear regression. This trial is registered with ClinicalTrials.gov, NCT03494777. Results: Neither incentive arm increased adherence compared to the control; we estimate a 3.9 percentage point increase in ‘adherence-linked’ arm [95% CI -0.70 to 8.60 (p=0.10)], and 0.024 in the ‘clinic-linked’ arm [95% CI -0.02 to 0.07 (p=0.28)]. For the prespecified subgroup of those with initial low adherence, incentives increased adherence by 7.60 percentage points (95% CI 0.01, 0.15; p=0.04, ‘adherence-linked’) and 5.60 percentage points (95% CI -0.01, 0.12; p=0.10, ‘clinic-linked’). We find no effects on clinic attendance or viral suppression. Conclusions: Incentives did not improve viral suppression or ART adherence overall but worked for the pre-specified subgroup of those with initial low adherence. More effectively identifying those in need of adherence support will allow better targeting of this and other incentive interventions.