METHODS: This retrospective cohort study involved laboratory-confirmed drug-resistant TB patients from January 2009 to June 2013. Multiple logistic regression was used to model the outcome, which was subsequently defined according to the recent definition by the WHO. Data were analysed using IBM SPSS Statistics for Windows version 22.0.

RESULTS: Among the 403 patients who were analysed, 66.7% of them were found to have achieved successful outcomes (cured or completed treatment) while the remaining 33.3% had unsuccessful treatment outcomes (defaulted, treatment failure or died). Multivariable analysis showed that the type of resistance [polyresistant (aOR = 3.00, 95% CI 1.14-7.91), multidrug resistant (MDR) (aOR = 5.37, 95% CI 2.65-10.88)], ethnicity [Malay (aOR = 2.86, 95% CI 1.44-5.71), Indian (aOR = 3.04, 95% CI 1.20-7.70)], and treatment non-compliance (aOR = 26.93, 95% CI 14.47-50.10) were the independent risk factors for unsuccessful treatment outcomes among this group of patients. Notably, the odds of unsuccessful treatment outcome was also amplified among Malay MDR-TB patients in this study (aOR = 13.44, 95% CI 1.99-90.58).