Tuberculosis preventive therapy for HIV-infected people in sub-Saharan Africa is cost-effective

Objective: Since antiretroviral therapy is largely unavailable to HIV-infec ted patients in developing countries and recent clinical trials have shown that tuberculosis (TB) preventive therapy can reduce TB and HIV-associated morbidity and mortality, we studied the effectiveness and cost-effectivenes s of TB preventive therapy for HIV-infected persons in sub-Saharan Africa. Methods: A Markov model that used results of clinical trials of TB preventi ve therapy in sub-Saharan Africa and literature-derived medical care costs was used to evaluate three preventive therapy regimens in HIV-infected, tub erculin-positive patients in Uganda: (1) daily isoniazid (INH) for 6 months , (2) daily INH and rifampin (RIF) for 3 months, and (3) twice-weekly RIF a nd pyrazinamide (PZA) for 2 months. Results: All three regimens extend life expectancy and reduce the number of TB cases. When only medical care costs are considered, all three preventiv e therapy regimens cost more than not providing preventive therapy to exten d life and prevent active tuberculosis. When medical care and social costs are considered together, 6-months of daily INH treatment will save money re lative to no preventive therapy and when the costs associated with treating secondary infections are included, all three preventive therapy regimens a re less expensive than no preventive therapy. With the inclusion of seconda ry infection costs, 6 months of daily INH results in savings of $24.16 per person. Conclusions: TB preventive therapy taken by HIV-infected tuberculin reactor s in sub-Saharan Africa results in extended life-expectancy, reduction of t he incidence of TB and monetary savings in medical care and social costs. T B control policy in sub-Saharan Africa should include preventive therapy. ( C) 1999 Lippincott Williams & Wilkins.