Prevalence trends, population characteristics and treatment outcomes of tuberculosis combined with diabetes in southwest China: a register-based retrospective study

The global situation regarding the prevention and control of pulmonary tuberculosis (PTB) remains challenging. With the ongoing aging population and the increasing prevalence of chronic diseases, the epidemic of comorbid PTB and diabetes mellitus (PTB-DM) presents challenges to PTB control .This study aims to explore the epidemiological trends of PTB-DM in Southwest China and identify risk factors associated with adverse treatment outcomes, providing evidence to enhance TB prevention and control measures and improve patient treatment outcomes.This retrospective study used PTB case data from the PTB Information Management System within the China Information System for Disease Control and Prevention (CISDP). The trend in PTB-DM incidence was analyzed using the Joinpoint regression model, and population and clinical characteristics of patients were described using frequencies (n) and percentages. Group comparisons utilized chi-square tests, and risk factors for adverse treatment outcomes were explored using multivariable logistic regression models with stepwise backward selection based on Wald tests.The Joinpoint analysis revealed a declining trend in PTB incidence in Southwest China (AAPC = -10.22%, 95% CI: -11.49%~-8.94%), contrasting with a rapid increase in PTB-DM incidence (AAPC = 14.25%, 95% CI: 11.35% ~17.23%). The proportion of PTB-DM among PTB cases increased significantly from 2.96% to 12.28%, indicating a pronounced increase in the comorbidity prevalence of PTB-DM. PTB-DM patients were characterized by a higher proportion of males and elderly individuals, multiple positive aetiological results, and lower rates of proactive medical consultation. Among PTB-DM patients, successful outcomes accounted for 80.85% , while unsuccessful outcomes accounted for 19.15%.Although the number of PTB-DM patients with successful treatment outcomes increased overall (AAPC = 12.22%, 95% CI: 10.30% ~14.16%), the failure rate showed a gradual upward trend (AAPC = 14.18%, 95% CI: 6.53% ~27.67%). Analysis of factors associated with adverse treatment outcomes showed that advanced age, retreatment, referral, and positive aetiological results were risk factors for PTB-DM patients.Therefore, it is imperative to strengthen early screening and standardized treatment for key populations, such as the elderly population, and to implement more comprehensive and effective treatment and management measures for patients.