Outcomes and predictors of tuberculosis mortality in Kweneng West District, Botswana: a retrospective cohort study

Introduction: Botswana is among the countries with the highest tuberculosis (TB) notification rates in the world. However, there is paucity of data on the outcomes and predictors of TB mortality at district level in Botswana. This study was aimed at describing the TB outcomes and identifying the predictors of mortality in Kweneng West district, Botswana. Methods: this was a retrospective cohort study of TB outcomes in Kweneng West, from January 2008 to December 2016. All documented drug-sensitive TB (DS-TB) patients aged 16 years and above were included. The World Health Organization (WHO) definitions of treatment outcomes for DS-TB were used. Binary logistic regression was used to identify predictors of mortality. Results: there were 1475 TB notifications in the study period. The median age was 36 years and 41.5% were female. A total of 728 (49.4%) were HIV positive. Pulmonary TB (PTB) accounted for 87.3% of all cases. The overall treatment success rate (TSR) was 81.9% and the mortality rate was 9.4%. Compared to the 16-25 years age group, patients aged more than 65 years had the highest risk of mortality (AOR=9.63). Other significant predictors of mortality were male sex (AOR=1.63), no sputum microscopy (AOR=1.77), positive HIV (AOR=2.13) and unknown HIV status (AOR=4.47). Positive sputum microscopy (AOR=0.50) and extrapulmonary TB (EPTB) (AOR=0.56) were associated with less mortality. Conclusion: while Botswana has relatively good TB treatment success rates, the mortality rates are high. Public health interventions should target the identified risk factors of mortality.