Estimation of mortality among HIV-infected people on antiretroviral therapy treatment in East Africa: a sampling based approach in an observational, multisite, cohort study

Abstract

Background—Mortality after initiation of antiretroviral treatment (ART) among HIV-infected patients in resource limited settings is a critical measure of the effectiveness and comparative effectiveness of the global public health response. Unknown outcomes due to high loss to followup (LTFU) preclude accurate accounting of deaths and limit our understanding of effectiveness. Methods—We evaluated in HIV-infected adults on ART in 14 clinics in five settings in Kenya, Uganda and Tanzania using a sampling-based approach in which we intensively traced a random sample of lost patients (> 90 days late for last scheduled visit) and incorporated their vital status outcomes into analyses of the entire clinic population through probability-weighted survival analyses. Findings—We followed 34,277 adults on ART from Mbarara and Kampala, Uganda; Eldoret and Kisumu, Kenya; and Morogoro, Tanzania. The median age was 35 years, 34% were men, and median pre-therapy CD4 count was 154 cells/μl. Overall 5,780 (17%) were LTFU, 991 (17%) were randomly selected for tracing and vital status was ascertained in 860 of 991 (87%). Incorporating outcomes among the lost increased estimated 3-year mortality from 3.9% (95% CI: 3.6%-4.2%) to 12.5% (95% CI: 11.8%-13.3%). The sample-corrected, unadjusted 3-year mortality across settings ranged from 7.2% in Mbarara to 23.6% in Morogoro. After adjustment for age, sex, pre-therapy CD4 value, and WHO stage, the sample-corrected hazard ratio comparing the setting with highest vs. lowest mortality was 2.2 (95% CI: 1.5-3.4) and the risk difference for death at 3 years was 11% (95% CI: 5.0%-17.7%). Author Manuscript Author Manuscript Author Manuscript Interpretation—A sampling based approach is widely feasible and important for understanding mortality after starting ART. After adjustment for measured biological drivers, mortality differs substantially across settings despite delivery of a similar clinical package of treatment. Implementation research to understand the systems, community, and patient behaviors driving these differences is urgently needed.