Abstract: Objective: To investigate the influencing factors of recurrence within 2 years after successful treatment of newly treated active tuberculosis in Tianjin. Methods: Medical records of 8115 newly treated active tuberculosis patients registered in Tianjin City from January 1, 2016 to December 31, 2019 were retrieved from Tuberculosis Management Information System, a sub-system of Chinese Disease Control and Prevention Information System. Cox proportional risk model was used to analyze the general information, clinical information, etiological results and treatment outcomes of them. Results: Among the 8115 patients, 307 patients recurred within 2 years, the recurrence rate was 3.78%. The recurrence density was 0.85 per 100 person-years (307/36104),the proportion of recurrence within 6 months was 35.83% (110/307), 29.00% (89/307) within 6-12 months, and 35.17% (108/307) in 1-2 years. Among subjects enrolled from 2016 to 2019, the recurrence rates within 2 years were 4.20% (102/2427),4.03% (96/2383),3.53% (86/2433),2.64% (23/872) respectively, which decreased year by year ( {\chi }_{\mathrm{trend}}^2=4.517, P=0.034).Cox proportional risk regression model showed that male (aHR=1.321,95%CI:1.021-1.710), 40-59 years old (aHR=2.220,95%CI:1.224-4.025), ≥60 years old (aHR=1.935,95%CI: 1.066-3.513), worker/migrant worker/herdsmen (aHR=2.303, 95%CI: 1.233-4.303), houseworker/unemployment (aHR=2.340,95%CI: 1.322-4.143), positive etiological result (aHR=1.785,95%CI:1.407-2.265), resistance to non-rifampicin drugs (aHR=1.968, 95%CI: 1.389-2.789), sputum smear positive after 2 months’ treatment (aHR=1.517,95%CI:1.033-2.228), complicated with diabetes mellitus (aHR=1.382, 95%CI: 1.028-1.857) were independent risk factors for recurrence. Conclusion: The risk of recurrence of newly treated active tuberculosis patients in Tianjin City was relatively high. We should focus on the standardized treatment and follow-up management of people over 40 years old, workers/farmers/herdsmen/unemployed patients, and patients with positive etiological results/non-rifampicin resistance/positive sputum smear results after 2 months’treatment/diabetes. Specialized intervention measures should be put on these high-risk groups in early stages.

Key words: Tuberculosis, pulmonary, Recurrence, Epidemiologic studies, Risk factors, Tianjin