Material and Method: Adult patients who had smear-positive pulmonary TB treated at Srinagarind Hospital between January 2005 and December 2010 were enrolled in the present study.

Results: Over a 6-years period, 322 patients (272 new and 50 previously-treated cases) were diagnosed smear positive pulmonary TB. The mean age was 48.85 (SD 17.9) years and the male to female ratio was 1.8:1. The mean duration of symptoms in the previously-treated group was longer than the new cases (2.39 vs. 1.99 months, p = 0.38). Symptoms, underlying diseases, HIV status, and organ involvement between these two groups were not different. Two-thirds (72.1% of patients) had cough, 35.4% had fever, and 20.5% weight loss. Twenty-three percent of cases had underlying DM and 7.8% were HIV positive. Disseminated TB was found in 18.9% of cases. The mean duration of treatment in new cases was 6.88 months vs. 11.20 months in previously-treated cases. The common regimens for new cases included 2IRZE/4IR (72.8%) and 2IRE/7IR (19.1%) vs. 2IRZE/4IR (62%), 2IRE/7IR (12%), and other regimens for MDR patients (6%) among the previously-treated cases. However in previously-treated group IRZES/IRZE/IRE (p = 0.001), second-line drugs (p = 0.002), and MDR regimens (p<0.001) were statistically more common treatments than in the new cases group. About 60% of cases were treated at TB clinic. The success rate among new cases who had completed treatment at Srinagarind Hospital was higher than for previously-treated ones (94.8% vs. 86.4%; p = 0.04). Among previously-treated cases (n = 50); 24 were defaulters, 19 were relapses, and seven were failures. For the defaulted and relapsed cases, patients usually received the IRZE/IR or IRZES/IRZE/IRE regimens. On the other hand, for failure cases, patients usually received the second-line drugs or MDR regimens. The overall success rate in defaulted cases was 87.6%, vs. 68.4% who relapsed and 57.1% who failed (p = 0.067). For new cases, the isolations found DR-TB 3.6% and MDR-TB 0%. For previously-treated cases, the isolations found DR-TB 16.67% and MDR-TB 6.25%. The only one factor related to successful outcomes was treatment at TB clinic (adjusted OR 2.01, 95% CI 1.18-3.43).

Conclusion: Previously-treated pulmonary TB had less success rate than new cases. Culture and susceptibility for previouslytreated group were recommended before starting treatment. Treatment at TB clinic improved treatment outcomes.

Keywords: Pulmonary TB, Treatment outcomes, Factors related to success