High mortality among tuberculosis patients on treatment in Nigeria: a retrospective cohort study

Background: Tuberculosis (TB) remains a leading cause of death in much of sub-Saharan Africa despite available effective treatment. Prompt initiation of TB treatment and access to antiretroviral therapy (ART) remains vital to the success of TB control. We assessed time to mortality after treatment onset using data from a large treatment centre in Nigeria. Methods: We analysed a retrospective cohort of TB patients that commenced treatment between January 2010 and December 2014 in Aminu Kano Teaching Hospital. We estimated mortality rates per person-months at risk (pm). Cox proportional hazards model was used to determine risk factors for mortality. Results: Among 1,424 patients with a median age of 36.6 years, 237 patients (16.6%) died after commencing TB treatment giving a mortality rate of 3.68 per 100 pm of treatment in this cohort. Most deaths occurred soon after treatment onset with a mortality rate of 37.6 per 100 pm in the 1(st) week of treatment. Risk factors for death were being HIV-positive but not on anti-retroviral treatment (ART) (aHR 1.39(1 . 04-1 . 85)), residence outside the city (aHR 3 . 18(2.28-4.45)), previous TB treatment (aHR 3.48(2.54-4.77)), no microbiological confirmation (aHR 4.96(2.69-9.17)), having both pulmonary and extra-pulmonary TB (aHR 1.45(1.03-2.02), and referral from a non-programme linked clinic/centre (aHR 3.02(2.01-4.53)). Conclusions: We attribute early deaths in this relatively young cohort to delay in diagnosis and treatment of TB, inadequate treatment of drug-resistant TB, and poor ART access. Considerable expansion and improvement in quality of diagnosis and treatment services for TB and HIV are needed to achieve the sustainable development goal of reducing TB deaths by 95% by 2035.