Predictors of death among tuberculosis patients while on treatment in local health facilities in Francistown
Background: Botswana has one of the highest TB incidence rates in the world. Tuberculosis in those without HIV infection accounts for 13% of adult mortality and in those living with TB and HIV in Botswana account for 40% of annual adult mortality. Francistown is a health district with TB mortality rates in excess of 5% of diagnosed TB patients yearly. The aim of this study was to assess patient related factors and early warning signs (predictors) of death among TB patients on treatment in Francistown clinics in order to identify possible interventions. Methodology: A retrospective case-control study design was used in this study. The records of all patients treated for TB from January 2010 to November 2015 who met the study inclusion criteria were extracted from the district electronic register (ETR). Socio-demographic variables, clinical variables and treatment outcome were collected and analysed. Univariate and multivariate logistic regression techniques were used to assess the predictors of death and the Kaplan Meier plot to determine time to death while on treatment. Result: A total of 1718 participants were included in the study. The median age of the study population was 35 years (IQR: 29, 42). Of the study population, 56% were male. Most of the participants had pulmonary TB (78%). There was a very high HIV prevalence among the study population (74%). About 44% of participants had smear results at the start and at the completion of TB treatment. Of the 1718 participants 161 (95% CI 8.0-10.8) died during the course of TB treatment. Univariate analysis showed HIV status, extra-pulmonary TB and a history of TB treatment default to be associated with earlier death. Multivariate analysis of selected variables showed that being older (≥ 55 years old), HIV-positive, having a history of TB and extra-pulmonary TB are independent predictors of death while on TB treatment. The overall median time to death was 52 days. Lack of HIV-related intervention during TB treatment was a significant independent predictor of time to death (adjusted HR = 1.79; 95% CI 1.03 – 3.1; p = 0.037). Conclusion: Of the 1718 adult patients treated for TB in Francistown clinics from January 2010 to November 2016, 161 (9%) died while on treatment. The predictors of death identified in the study include, prior history of TB infection, Extra-Pulmonary TB, HIV status, HIV-related intervention and over 55 years of age. Gender was not a predictor of death in this study. Their overall median time to death in the study was 52 days. Patients on treatment for the first time with no previous history of TB lived on average 150 days on TB treatment. All TB patients with HIV co-infection that did not receive Antiretroviral Therapy (ART) and or Cotrimoxazole Preventive Therapy (CPT) died during the intensive phase of TB treatment. More than half of all deaths recorded in this study occurred during the intensive phase of TB treatment. After adjusting for gender, age, treatment classification, treatment group and HIV status and the lack of HIV-related interventions during TB treatment was the significant predictor of earlier death among patients with TB/HIV co-infection in this study.