Abstract:
INTRODUCTION : South Africa is among countries with the highest burden of drug resistant tuberculosis
(DR-TB). The Eastern Cape Province reported the highest MDR-TB mortality rates in South
Africa for the 2010 treatment cohorts. This study aimed to determine risk factors for mortality
among adult patients registered for DR-TB treatment in the province.
METHODS : We conducted a retrospective cohort study of adult patients treated for laboratory confirmed
DR-TB between January 2011 and December 2013. Demographic and clinical characteristics
of the patients were obtained from a web-based electronic database of patients treated
for DR-TB. We applied modified Poisson regression with robust standard errors to identify
risk factors for DR-TB mortality. We also stratified the analyses into multi-drug resistant TB
(MDR-TB) and extensively drug resistant (XDR-TB).
RESULTS : Among 3,729 patients that met the inclusion criteria, 39% (n = 1,445) died. Of the patients
that died, 53% (n = 766) were male, 68% (n = 982) had MDR-TB, 72% (n = 1,038) were HIV
co-infected, and median age was 37 years (Interquartile Range [IQR] 30±46). Patients were
at higher risk of mortality during DR-TB treatment if they were HIV co-infected not on antiretroviral
treatment (ART) (adjusted incidence risk ratio [aIRR] 3.3, 95% confidence interval
[CI] 2.9±3.8), were 60 years or older (aIRR 1.7, 95%CI 1.5±2.0), had a diagnosis of XDR-TB (aIRR 1.6, 95%CI 1.5±1.7), or had been hospitalised at treatment start (aIRR 1.7, 95%CI
1.5±1.8). Among MDR-TB patients, risk of mortality was higher if patients were HIV coinfected
not on ART (aIRR 3.9, 95%CI 3.3±4.6), were 60 years or older (aIRR 1.9, 95%CI
1.6±2.3), or had been hospitalised at start of MDR-TB treatment (aIRR 1.7, 95%CI 1.5±1.9).
Among XDR-TB patients, risk of mortality was higher in patients who were HIV co-infected
not on ART (aIRR 1.8, 95%CI 1.5±2.2), or had been hospitalised at the start of XDR-TB
treatment (aIRR 1.5, 95%CI 1.3±1.8).
CONCLUSION : HIV co-infected not on ART, older age, XDR-TB and hospital admission for DR-TB treatment
were independent risk factors for DR-TB mortality. Integration of TB and HIV services,
with focus on voluntary HIV testing and counselling of DR-TB patients with unknown HIV
status, and provision of ART for all co-infected patients may reduce DR-TB mortality in the
Eastern Cape.
