Effect of non-monetary incentives on uptake of couples' counselling and testing among clients attending mobile HIV services in rural Zimbabwe: a cluster-randomised trial

Summary Background Couples' HIV testing and counselling (CHTC) is associated with greater engagement with HIV prevention and care than individual testing and is cost-effective, but uptake remains suboptimal. Initiating discussion of CHTC might result in distrust between partners. Offering incentives for CHTC could change the focus of the pre-test discussion. We aimed to determine the impact of incentives for CHTC on uptake of couples testing and HIV case diagnosis in rural Zimbabwe. Methods In this cluster-randomised trial, 68 rural communities (the clusters) in four districts receiving mobile HIV testing services were randomly assigned (1:1) to incentives for CHTC or not. Allocation was not masked to participants and researchers. Randomisation was stratified by district and proximity to a health facility. Within each stratum random permutation was done to allocate clusters to the study groups. In intervention communities, residents were informed that couples who tested together could select one of three grocery items worth US$1·50. Standard mobilisation for testing was done in comparison communities. The primary outcome was the proportion of individuals testing with a partner. Analysis was by intention to treat. 3 months after CHTC, couple-testers from four communities per group individually completed a telephone survey to evaluate any social harms resulting from incentives or CHTC. The effect of incentives on CHTC was estimated using logistic regression with random effects adjusting for clustering. The trial was registered with the Pan African Clinical Trial Registry, number PACTR201606001630356. Findings From May 26, 2015, to Jan 29, 2016, of 24 679 participants counselled with data recorded, 14 099 (57·1%) were in the intervention group and 10 580 (42·9%) in the comparison group. 7852 (55·7%) testers in the intervention group versus 1062 (10·0%) in the comparison group tested with a partner (adjusted odds ratio 13·5 [95% CI 10·5–17·4]). Among 427 (83·7%) of 510 eligible participants who completed the telephone survey, 11 (2·6%) reported that they were pressured or themselves pressured their partner to test together; none regretted couples' testing. Relationship unrest was reported by eight individuals (1·9%), although none attributed this to incentives. Interpretation Small non-monetary incentives, which are potentially scalable, were associated with significantly increased CHTC and HIV case diagnosis. Incentives did not increase social harms beyond the few typically encountered with CHTC without incentives. The intervention could help achieve UNAIDS 90-90-90 targets. Funding The study was funded by the UK Department for International Development, Irish AID, and Swedish SIDA, through Population Services International Zimbabwe under the Integrated Support Program.