Factors contributing to the high prevalence of multidrug-resistant tuberculosis among previously treated patients: a case-control study from China.

Setting: Multidrug-resistant tuberculosis (MDR-TB) has emerged as a serious global public health problem. In China, the risk factors for MDR-TB have not been systematically evaluated. Objective: To identify risk factors associated with MDR-TB among previously treated patients in China. Design: A case-control study was carried out. Cases were selected from previously treated MDR-TB patients who were resistant to both isoniazid and rifampin, and controls were selected from previously treated TB patients who were sensitive to isoniazid and rifampin (non-MDR-TB). Information was collected from the registration database and a structured questionnaire. Results: A total of 61 cases and 50 controls were recruited. A multivariate analysis showed that the family annual per-capita income <= 7,000 Yuan (odds ratio [OR] = 3.238; 95% confidence interval [CI]: 1.270-8.252), no history of fixed dose combinations (FDCs) in anti-TB treatment (OR = 4.027; 95% CI: 1.457-11.129), and adverse reactions in the course of TB treatment (OR = 3.568; 95% CI: 1.402-9.085) were independent predictors of MDR-TB. Moreover, among the TB patients who had adverse reactions, quitting the treatment was shown as a risk factor for MDR-TB (p = 0.009). Conclusion: In the control of MDR-TB among previously treated patients, lower socioeconomic groups, the expanding use of FDCs, and improving adherence to treatment by implementing Directly Observed Therapy Short Course-Plus (DOTS-Plus), strictly should become a priority that requires strong commitment and collaboration among health organizations.