The Drinkers’ Intervention to Prevent Tuberculosis (DIPT) trial among heavy drinkers living with HIV in Uganda: study protocol of a 2×2 factorial trial

Abstract

Background: The risk of tuberculosis (TB) is high among people with HIV (PWH). Heavy alcohol drinking independently increases TB risk and approximately 25% of PWH globally engage in heavy drinking. While isoniazid (INH) preventive therapy decreases TB incidence and mortality among PWH, heavy drinking during INH is associated with liver toxicity and poor adherence. Interventions are, therefore, urgently needed to decrease alcohol use and improve adherence to INH in this population in settings with high prevalence of HIV and TB like Uganda. Methods: The Drinkers’ Intervention to Prevent TB (DIPT) study is a 2×2 factorial randomized controlled trial among HIV/TB co-infected adults (≥18 years) who engage in heavy alcohol drinking and live in Uganda. The trial will allocate 680 participants with a 1:1:1:1 individual randomization to receive 6 months of INH and one of the following interventions: (1) no incentives (control), (2) financial incentives contingent on low alcohol use, (3) financial incentives contingent on high adherence to INH, and (4) escalating financial incentives for both decreasing alcohol use and increasing adherence to INH. Incentives will be in the form of escalating lottery-based monetary rewards. Participants will attend monthly visits to refill isoniazid medications, undergo liver toxicity monitoring, and, except for controls, determine eligibility for prizes. We will estimate (a) the effect of incentives contingent on low alcohol use on reduction in heavy drinking, measured via a long-term objective and self-reported metric of alcohol use, at 3- and 6-month study visits, and (b) the effect of incentives contingent on high adherence to INH, measured as >90% pill-taking days by medication event monitoring system cap opening. We will use qualitative methods to explore the mechanisms of any influence of financial incentives on HIV virologic suppression. Discussion: This study will provide new information on low-cost strategies to both reduce alcohol use and increase INH adherence among people with HIV and TB infection who engage in heavy drinking in low-income countries with high HIV and TB prevalence.