Risk factors for pulmonary tuberculosis recurrence in Henan, China, from 2014 to 2024

Pulmonary tuberculosis (TB) recurrence is a significant risk factor for the development of drug-resistant (DR) TB. Understanding the risk factors associated with pulmonary tuberculosis (PTB) recurrence is crucial for designing targeted interventions to end the TB epidemic. In Henan Province, China, where the PTB incidence rate was 37.09 per 100,000 in 2023, we conducted a retrospective cohort study. This study utilized passive monitoring to investigate the rate and predictors of bacteriological recurrence within 5 years after cure in a cohort of newly diagnosed PTB patients. A retrospective cohort analysis was carried out using data from the China Information System for Disease Control and Prevention (CISDCP), focusing on bacteriologically confirmed PTB patients who were diagnosed between 2014 and 2019 and cured in Henan Province, China. A five-year follow-up was conducted via passive monitoring to calculate the recurrence time and recurrence rate, as well as to identify risk factors associated with bacteriological recurrence. For univariate analysis, the Kaplan-Meier method was used. The log-rank test was employed for between-group comparisons. Multivariable analysis was performed using a Cox proportional hazards (PH) regression model, with results reported as adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). Among the 53,124 cured PTB patients, 1346 experienced recurrence, yielding a 5-year cumulative recurrence rate of 2.53%. The recurrence density was 5.14 per 1,000 person-years (PYs). The median recurrence interval was 500.50 days (IQR: 217.00-940.75). Multivariable Cox regression revealed the top three risk factors associated with recurrence. Older age (≥ 45 years) was the strongest: compared with the reference group aged 15-24 years, the adjusted hazard ratio (aHR) was 2.659 (95% CI: 2.132-3.317) for patients aged 45-64 years and 1.958 (95% CI: 1.554-2.467) for those aged ≥ 65 years. Bacteriological positivity at month 2 or 3 of treatment (aHR = 1.877, 95% CI: 1.428-2.467) and male sex (aHR = 1.826, 95% CI: 1.573-2.119) were the other two key factors. Other significant factors associated with increased recurrence risk included the presence of comorbidities (aHR = 1.521), positive culture at month 0 (aHR = 1.319), being a member of the floating population (aHR = 1.205), and patient delay (aHR = 1.205). In contrast, receiving entire-episode directly observed therapy (DOT) served as a significant protective factor against PTB recurrence (aHR = 0.696, 95% CI: 0.545-0.889). The PTB recurrence rate in Henan is relatively low. Key risk factors included age ≥ 45 years, bacteriological positivity at month 2 or 3 of treatment, and male sex. Receiving entire-episode DOT was identified as a protective factor. Accordingly, public health education should be strengthened to promote timely medical consultation. Standardized treatment regimens, entire-episode DOT or video-observed therapy (VOT), early drug resistance testing, and comorbidity control are essential. Enhanced support should be provided to PTB patients who are male or belong to the floating population. Active follow-up and management procedures after cure should be implemented to reduce recurrence rates.