Abstract:

Objective To investigate the sputum culture conversion (SCC) at the end of 6 months and related risk factors among patients with multidrug-resistant pulmonary tuberculosis (MDR-PTB).Methods Retrospective cohort study was conducted among 365 MDR-PTB patients who were diagnosed and started anti-TB drug treatment during 2011 and 2015 in designated TB hospitals in Hangzhou. Demographic information and laboratory results were collected to analyze the SCC at the end of 6 months, and identify the related risk factors using the Hazard Cox regression Model.Results Of 365 enrolled participants, 332 were negative at the end of 6 months with the SCC rate of 90.96%; 287 (78.63%) were successfully treated, and 78 (21.37%) were unsuccessful. The median (Q₁, Q₃) time of SCC in the 332 SCC subjects was 85.0 (42.0, 106.5) d, of which 84.94% (282 cases) were successfully treated. Among the 33 cases without SCC, the treatment success rate was 15.15% (5 cases). Significant higher treatment success rate was observed among the participants who initialed SCC at 6 months than the participants who did not (χ ²=87.00,P=0.000). Cox regression analysis revealed that compared with patients without household registration in Hangzhou, patients with household registration in Hangzhou were more likely to initial SCC (SCC rate: 4.09/100 person years (149/36.41), adjusted hazard ratio (aHR) (95%CI): 1.37 (1.10-1.71)); compared with patients who were resistant to less than 4 drugs and aged <25 years old, patients who were resistant to no less than 4 drugs (SCC rate: 3.36/100 person years (119/35.43), aHR (95%CI): 0.76 (0.61-0.96)) and aged ≥25 years old (25-44 years group, SCC rate: 3.69/100 person years (143/38.80), aHR (95%CI): 0.56 (0.41-0.78); 45-64 years group, SCC rate: 3.36/100 person years (108/32.15), aHR (95%CI): 0.52 (0.37-0.73); ≥65 years group, SCC rate: 3.33/100 person years (27/8.10), aHR (95%CI): 0.45 (0.38-0.72)) were less likely to initial SCC. Conclusion The treatment success rate and SCC rate at the end of 6 months were relatively high in MDR-PTB patients in Hangzhou, while it costs longer time to initial SCC at the end of 6 months. Patients without Household registration in Hangzhou, patients with more resistant drugs and elder patients should be especially supervised and managed at early stage during their treatment to improve the treatment outcomes.

Key words: Tuberculosis,pulmonary, Tuberculosis,multidrug-resistant, Mycobacterium tuberculosis, Sputum, Treatment outcome, Regression analysis