Drinkers' Intervention to Prevent Tuberculosis (DIPT Study)

TB is the leading cause of death among persons with HIV worldwide, and HIV-infected drinkers are at very high risk for TB disease and mortality. Globally, an estimated 25% of persons with HIV are heavy drinkers, and the risk of TB disease is 3-fold higher among heavy drinkers compared to non-drinkers. Six months of isoniazid (INH) preventive therapy (IPT) reduces TB morbidity and mortality by 30-50% above the benefit of antiretroviral therapy (ART). However, INH can be toxic to the liver, and as a result in many high TB/HIV prevalence settings, such as east Africa, heavy drinkers are not offered IPT. Thus interventions to reduce alcohol use are needed to decrease INH toxicity during IPT among HIV/TB infected drinkers. It is also well established that heavy drinkers have poorer ART adherence, and there is growing evidence of reduced IPT adherence in drinkers. However, interventions to reduce drinking have had limited impact on ART adherence, and further interventions to increase IPT adherence among HIV/TB infected drinkers are likely needed.

The use of incentives to promote healthy behavior is a highly effective approach for reducing substance use and for improving adherence to HIV and TB regimens in resource-rich settings. Economic incentives to reduce alcohol use may create a window for safe and effective IPT use over six months by decreasing hepatotoxicity. Decreases in alcohol use may also improve IPT adherence, or additional incentives for IPT adherence may be needed. Such strategies to reduce alcohol use have not been studied in low-income countries and the effectiveness of incentives to optimize IPT in HIV/TB co-infected drinkers is unknown.

OBJECTIVES

Aim 1: Alcohol Reduction Intervention: Determine the effectiveness of economic incentives contingent on point-of-care (POC) urine ethyl glucuronide (EtG) <300 ng/mL (Arms 2 & 4) versus no alcohol incentives (Arms 1 & 3) to reduce heavy drinking over 6 months, among HIV/TB co-infected adult drinkers receiving IPT. The investigators will randomize participants to low-cost escalating prize incentives for EtG negative urine tests at IPT refill visits (Arms 2+4), versus no incentives (Arms 1+3).

Aim 2: INH Adherence Intervention: Determine the effectiveness of economic incentives contingent on POC (IsoScreen) INH urine positive tests (Arms 3 & 4) versus no INH incentives (Arms 1 & 2) on INH adherence among HIV/TB co-infected adult drinkers. The investigators will randomize participants to low-cost escalating prize incentives for INH positive urine tests at IPT refill visits (Arms 3+4), versus no incentives (Arms 1+2).

Aim 3: Impact Assessment of Intervention: Assess the impact of economic incentives on HIV virologic suppression and explore their mechanisms of action, six months after trial completion. The investigators will follow all study participants for six months after trial completion.

• Assess the impact of the 3 separate incentive interventions (Arms 2, 3, 4) vs. no incentives (Arm 1) on HIV virologic suppression.
• Explore the mechanisms that may drive the economic incentives to increase virologic suppression. Potential mediators will be reductions in alcohol use and level of IPT adherence.

This study will leverage new low-cost POC tests for alcohol use and INH pill-taking for the first study of incentive-based alcohol and adherence interventions in low-resource settings; these interventions may improve the safety and effectiveness of life-saving medications for heavy alcohol users in many settings.

Inclusion criteria

• HIV-infected adult (≥18 years) prescribed antiretroviral therapy (ART) for at least 6 months;
• Current heavy alcohol use (AUDIT-C positive for prior 3 month drinking and positive EtG urine test);
• Positive tuberculin skin test (TST) (≥5 mm induration);
• AST and ALT <2x the upper limit of normal (ULN);
• Fluent in Runyankole or English;
• No history of active TB, TB treatment, or TB preventive therapy;
• Lives within 2-hour travel time or 60 km of the study site.

Exclusion criteria

• Prescribed nevirapine (NVP, an ART drug that is declining in usage due to high risk for hepatotoxicity);
• Plans to move out of the catchment area within 6 months;
• Prescribed anti-convulsion medications or history of recurring seizures;
• ALT or AST elevations (>2X ULN);
• Suspected or confirmed active TB as determined by symptom screening and followed by chest X-ray and sputum testing;
• History of prior active TB treatment or prior IPT.
• Pregnant at time of screening