Survival and predictors of mortality after completion of TB treatment among people living with HIV

BackgroundAfter completion of TB treatment patients may remain at-risk of complications and mortality. We determined the survival and predictors of all-cause mortality after completing TB treatment among ART experienced patients. MethodsThis was a retrospective cohort analysis of all ART experienced patients who completed TB treatment at a specialist HIV clinic in Uganda, between 2009 and 2014. The patients were followed for five years after TB treatment. We determined mortality rate, probability of death, and predictors of all-cause mortality after TB treatment using Poisson methods, Kaplan-Meier methods, and Cox proportional hazard models, respectively. ResultsA total 1,287 patients completed TB treatment between 2009 and 2014, of which 1,111 were included in the analysis. At TB treatment completion, the median age was 36 years (IQR: 31-42), 563 (50.7%) were males, and median CD4 count was 235 cells/mL (IQR: 139-366). The person time at risk was 4410.60 person-years. The all-cause mortality rate was 15.42 per 1000 person-years (95% CI: 12.14-19.59). The probability of death at five years was 6.9% (95%CI: 5.5%-8.8%). In the multivariable analysis, CD4 count<200 cells/mL was a predictor of all-cause mortality (aHR=1.81, 95%CI:1.06 - 3.11, p=0.03) alongside TB history (aHR=2.12, 95%CI: 1.16 - 3.85, p=0.01). ConclusionSurvival post TB treatment in ART experienced PLHIV is reasonably good and most deaths occur within two years of TB treatment completion. Patients with low CD4 and those with history of treatment have an increased risk of mortality which underscores the need for TB prophylaxis, detailed assessment, and close monitoring after TB treatment. What is already known on this topicTuberculosis is the leading cause of death in PLHIV and patients who complete treatment remain at risk of mortality. However, it is not clear what the mortality rate is, when it occurs, and what factors are associated with mortality in exclusively ART experienced patients. What this study addsMost deaths occur within two years after treatment completion decreasing drastically by year five. Patients with low CD4 count after TB treatment have an 81% increased risk of death and those with a history of TB have a 200% increased risk of mortality. How this study might affect research, practice or policyThe study provides a detailed understanding of post-TB survival in ART experienced PLHIV and underscores the need for programs and clinics to re-define TB treatment success and consider the use of enhanced prophylaxis after TB treatment.