HIV co-infection increases the risk of post-tuberculosis mortality among patients treated for drug resistant tuberculosis

BACKGROUND: We aimed to determine the relationship between common pre-existing comorbidities in patients with tuberculosis (TB) (including human immunodeficiency virus [HIV], diabetes, and hepatitis C virus [HCV]) with rates of all-cause mortality after TB treatment. METHODS: We conducted a retrospective cohort study among patients treated for rifampicin-resistant and multi/extensively drug resistant (RR and M/XDR) TB in the country of Georgia during 2009-2017. Eligible participants were >15 years of age with newly diagnosed, laboratory-confirmed drug resistant TB who received second-line treatment. Exposures included HIV serologic status, diabetes, and HCV status. The primary outcome was post-TB treatment mortality determined by cross-validating vital status with Georgia’s national death registry through November 2019. We estimated hazard rate ratios (HR) and 95% confidence intervals (CI) of post-TB mortality among participants with and without pre-existing comorbidities using cause-specific hazard regressions. RESULTS: Among 1032 eligible patients included in our analyses, 34 (3.3%) participants died during treatment and 87 (8.7%) died post-TB treatment. Among those who died post-TB treatment, the median time to death was 21 months (IQR 7–39) after TB treatment ended. After adjusting for potential confounders, the hazard rates of mortality post-TB treatment were higher among participants with HIV co-infection (adjusted hazard ratio [aHR]=3.74, 95%CI 1.77–7.91) compared to those without HIV co-infection. CONCLUSIONS: In our cohort, post-TB mortality occurred most commonly in the first three years after TB treatment ended. Additional post-TB care and follow-up, especially among patients with TB and comorbidities (especially HIV co-infection), may reduce rates of mortality post-TB treatment.