Incidence and determinants of tuberculosis among HIV-positive individuals in Addis Ababa, Ethiopia: A retrospective cohort study.

Objective: To assess the incidence and determinants of tuberculosis (TB) among HIV-positive individuals in selected health facilities of Addis Ababa, Ethiopia, during the period January 2013 to December 2018.

Methods: Data were collected from the records of 566 HIV-positive individuals. A retrospective cohort study design was employed. Data were entered into Epi Info 7 and analyzed using IBM SPSS Statistics version 20. TB incidence density was determined per 100 person-years. Time-to-event distributions were estimated using Kaplan-Meier estimates. Survival curves and hazards across different categories were compared using log-rank tests. Determinants were identified using the Cox proportional hazards model. The hazard ratio (HR) and 95% confidence interval (CI) were computed. A p-value <0.05 in the multivariate analysis was considered statistically significant.

Results: A total of 566 HIV-positive individuals were followed for 2140.08 person-years, giving a TB incidence density rate of 6.82/100 person-years (146, 25.8%). The highest incidence was observed within the first year of follow-up. Independent determinants were large family size (adjusted HR (AHR) 1.783, 95% CI 1.113-2.855), lower baseline CD4 (AHR 2.568, 95% CI 1.602-4.116), and baseline body mass index <18.5 kg/m (AHR 1.907, 95% CI 1.530-2.690). Being enrolled in antiretroviral treatment (AHR 0.066, 95% CI 0.045-0.98) and taking isoniazid prophylaxis treatment (AHR 0.202, 95% CI 0.108-0.380) had a protective effect.

Conclusions: TB is still a major cause of morbidity among HIV-positive individuals. Early HIV diagnosis, enrollment on antiretroviral treatment, and isoniazid prophylaxis treatment should be considered to decrease the TB risk.