Risk Factors for Poor Outcomes in Patients with Multi-Drug Resistant Tuberculosis in South Korea / 한양의대학술지

ABSTRACT

BACKGROUND/AIMS: Multidrug-resistant tuberculosis (MDR-TB) is an important public health problem in South Korea. MDR-TB is difficult to control, and treatment is less effective than for drug-sensitive tuberculosis. The aim of this report is to determine the risk factors for poor outcomes for MDR-TB. METHODS: We retrospectively and consecutively analyzed the clinical outcomes of MDR-TB patients registered at a single tuberculosis-specialized hospital in South Korea from January 2005 to February 2011. We used standard treatment outcome definitions for MDR-TB and used the combination of “defaulted”, “treatment failed”, and “died” as a composite poor outcome variable. We analyzed the risk factors associated with poor outcome. RESULTS: Among the 258 patients sampled, 91 (35.3%) had MDR-TB on their first tuberculosis infection, while 167 patients (64.7%) who had previously been treated for tuberculosis had MDR-TB over the study period. Treatment outcomes revealed that 207 patients (80.2%) were cured of their infection, 15 (5.8%) completed their treatment, one (0.4%) defaulted treatment, 6 (2.3%) died, and treatment failed for 29 patients (11.3%). Multivariate Cox proportional-hazards regression analysis found that poor outcome were associated with a body mass index <18.5 kg/m2 (hazard ratio [HR] 2.57; 95% confidence interval [CI] 1.28-5.15, p = 0.008), being susceptible to four or fewer drugs at the start of treatment (HR 3.89; 95% CI 1.38-10.96, p = 0.01), and ofloxacin resistance (HR 2.49; 95% CI 1.06-5.81, p = 0.035). CONCLUSIONS: Being underweight, susceptibility to four or fewer drugs, and ofloxacin resistance are independent prognostic factors of poor outcome for MDR-TB patients.