Clinical impact and cost-effectiveness of co-trimoxazole prophylaxis in patients with HIV/AIDS in Côte d’Ivoire: a trial-based analysis

Abstract

BACKGROUND: In 2000, WHO/UNAIDS recommended co-trimoxazole prophylaxis for persons at early stages of HIV infection (WHO stage > or = 2) in sub-Saharan Africa. OBJECTIVE: To assess the cost-effectiveness of alternative strategies for initiation of co-trimoxazole in Côte d'Ivoire. DESIGN: Cost-effectiveness analysis with an HIV simulation model using clinical and cost data from a randomized trial of co-trimoxazole in HIV-infected adults. METHODS: The study included HIV-infected patients in Côte d'Ivoire, with median age 33 years. Thirty-four percent were classified as WHO stage 2, 59% as stage 3, and 7% as stage 4. The mean CD4 cell count was 331 x 10(6) cells/l. The interventions were no prophylaxis, clinical criteria-based co-trimoxazole initiation (early: WHO stage > or = 2; late: WHO stage > or = 3), CD4-based co-trimoxazole initiation (< 500, < 200, < 50 x 10(6) CD4 cells/l). The outcome measures were life expectancy, lifetime costs, and incremental cost-effectiveness. RESULTS: The most effective strategy, initiation of co-trimoxazole prophylaxis at WHO stage > or = 2, increased undiscounted life expectancy by 5.2 months, discounted life expectancy by 4.4 months, and lifetime costs by US dollars 60, compared with no prophylaxis. Delaying prophylaxis initiation until WHO stage >or = 3 was less costly and less effective. All CD4-based strategies were dominated. The incremental cost-effectiveness of early versus late co-trimoxazole prophylaxis initiation was US dollars 200/year of life gained. Results were stable despite wide variations in plausible assumptions about bacterial resistance and the prophylaxis efficacy on co-trimoxazole-resistant strains. CONCLUSIONS: For HIV-infected adults in Côte d'Ivoire, co-trimoxazole prophylaxis is reasonably cost-effective and most effective if initiated when WHO stage > or = 2. Early co-trimoxazole prophylaxis will prevent complications prior to antiretroviral therapy initiation and should be considered an essential component of care for early HIV in sub-Saharan Africa.