Cost-utility of tuberculosis prevention among HIV-infected adults in Kampala, Uganda

SETTING: Treatment of latent tuberculosis (TB) infection using isoniazid preventive therapy (IPT) in a human immunodeficiency virus (HIV) volunteer counseling and testing center in Kampala, Uganda.

OBJECTIVE: To analyze the cost-utility of an IPT program for persons newly diagnosed with HIV.

DESIGN: The cost-utility analysis of the IPT program was conducted using Markov cohort simulation methods. Newly diagnosed HIV-infected persons were evaluated using tuberculin skin test (TST); those with positive TST were offered IPT for 9 months (targeted testing strategy). An alternative strategy of offering IPT to all HIV-infected clients without TST screening was also evaluated (treat all strategy). The cost-utility of targeted testing was compared to the ‘no program’ and the ‘treat all’ strategies.

RESULTS: The IPT program with the targeted testing strategy would produce 11 quality-adjusted life-years (QALYs) per 100 HIV-infected clients compared to no program. Offering IPT using the treat all strategy gained an additional 30 QALYs per 100 clients compared to targeted testing. Compared to no program, the incremental cost-utility of the targeted testing program was US$102/QALY gained. The cost-utility of the IPT program under the treat all strategy was US$106/QALY gained compared to the targeted testing strategy.

CONCLUSIONS: The provision of IPT for HIV-infected persons was cost-effective. The use of TST screening prior to IPT reduced costs per QALY gained, but saved fewer overall QALYs.