Population-based cohort study examining the association between weight loss and pulmonary tuberculosis in adults

Background/Purpose: Little research is currently available on the relationship between weight loss and pulmonary tuberculosis in Taiwan. This study aimed to evaluate whether weight loss is an early clinical feature of pulmonary tuberculosis in Taiwan. Method: This population-based retrospective cohort study was conducted using the Taiwan National Health Insurance Program database. There were 6051 subjects aged 20 to 84 years with newly diagnosed weight loss from 2000 to 2012 as the weight loss group, and 24081 randomly selected subjects without weight loss from the same period as the non-weight loss group. The weight loss and the non-weight loss groups were matched by sex, age, and comorbidities. The incidence of pulmonary tuberculosis at the end of 2013 was evaluated in both groups. A multivariable Cox proportional hazards regression model was used to evaluate the hazard ratio (HR) and 95% confidence interval (CI) for association of pulmonary tuberculosis with weight loss. Results: The incidence of pulmonary tuberculosis was 15.2-fold higher in the weight loss group than in the non-weight loss group during the first 3 months of follow-up (22.8 vs. 1.50 per 1000 person-years, 95% CI 13.7, 16.9). After adjusting for covariables, the subsequent HR of pulmonary tuberculosis was 2.36 for the weight loss group (95 % CI 1.88, 2.97), compared with the non-weight loss group. Conclusion: Although our finding is not novel, it does support the notion that weight loss is significantly associated with increased hazard of pulmonary tuberculosis in Taiwan. The risk was found to be particularly high during the first 3 months of follow-up.