Lottery incentives have short-term impact on ART initiation among men: results from a randomized pilot study

Introduction

Among people living with HIV in South Africa, viral suppression is lower among men than women. The study aim was to test the impact of lottery incentives, which reward positive health choice (e.g. antiretroviral therapy (ART) linkage) with a chance to win a prize, on strengthening the HIV care continuum including ART initiation and viral suppression for men.

Methods

We conducted a randomized, prospective trial of lottery incentives in the context of HIV testing and linkage to ART in rural KwaZulu-Natal, South Africa. Men living with HIV were randomly allocated to: lottery incentives and motivational text messages or motivational text messages only. Lottery prize eligibility was conditional on clinic registration, ART initiation, or viral suppression by one, three and six months respectively. After completing each continuum step, participants in the lottery group were notified whether they had won and were encouraged to continue in care. Lottery prizes were either a mobile phone, data or a gift card (valued at R1000/$100). Kaplan–Meier curves were plotted to determine time to ART initiation by study group. The primary outcome was viral suppression at six months.

Results

Between November 2017 and December 2018, we tested 740 men for HIV and enrolled 131 HIV-positive men who reported not being on ART. At baseline, 100 (76%) participants were 30 years and older, 95 (73%) were unemployed and the median CD4 count was 472 cells/μL. At study exit, 84% (110/131) of participants had visited a clinic and 62% (81/131) were virally suppressed. Compared to motivational text messages, lottery incentives decreased the median time to ART initiation from 126 to 66 days (p = 0.0043, age-adjusted Cox regression) among all participants, and, from 134 days to 20 days (p = 0.0077) among participants who were not virally suppressed at baseline. Lottery incentives had an inconclusive effect on clinic registration (RR = 1.21, 95% CI: 0.83 to 1.76) and on viral suppression at six months (RR = 1.13, 95% CI: 0.73 to 1.75) compared to motivational text messages.

Conclusions

Conditional lottery incentives shortened the time to ART initiation among South African men. Behavioural economics strategies strengthen linkage to ART, but the study power was limited to see an impact on viral suppression.