Pilot results of Masibambisane: couples motivational interviewing with mobile breathalyzers to address unhealthy drinking and adherence to antiretroviral therapy in South Africa

We evaluated the feasibility, acceptability, and preliminary efficacy of couples motivational interviewing (MI) with and without mobile breathalyzers (Masibambisane) to reduce unhealthy alcohol use among couples with HIV in KwaZuluNatal, South Africa. Ninety couples were randomized to couples MI with breathalyzers (MI-plus), couples MI without breathalyzers (MI-only), or enhanced usual care (EUC). Eligible couples had at least one partner on antiretroviral therapy (ART) with a positive AUDIT-C screen. Primary outcomes included retention, session attendance, breathalyzer completion, and satisfaction rates. Exploratory outcomes were unhealthy alcohol use (i.e., positive AUDIT-C screen and/or phosphatidylethanol [PEth]≥35 ng/ml), number of drinking days in past month, AUDIT-C score, optimal adherence to ART (95% or higher), and viral suppression. Retention and attendance rates were 97.7% and 83.3% at 6-months. Breathalyzer completion was limited (58.2%) due to cellular and power challenges. Satisfaction exceeded 94.8%. MI-only and MIplus arms had larger declines in drinking days and AUDIT-C score and larger increases in ART adherence vs. EUC. We observed no differences in biomarker-confirmed unhealthy alcohol use, which remained high across all arms at two months (94.6%, 96.5%, and 100%) for EUC, MI-only, and MI-plus. Viral suppression rates were 86.7%, 96.5%, and 86.2% for EUC, MI-only, and MI-plus. Between-arm differences for outcomes were non-significant; however, moderation analysis revealed that MI-only (p<0.001) and MI-plus (p<0.016) significantly reduced AUDIT-C scores for those with severe drinking (AUDIT-C>7). Masibambisane was highly feasible and acceptable. Results provide initial evidence of couples MI with breathalyzers to reduce alcohol use among those with very high-risk drinking.