Objective To investigate the spatiotemporal patterns of chronic bronchitis (CB) mortality and related influencing factors in Chongqing, and provide evidence for health interventions and effective disease prevention.

Methods Data were obtained from the Chongqing Center for Disease Control and Prevention, including records of CB deaths during 2012–2020. The CB mortality rates were calculated by using R 4.4.1 and χ² test was used for rate comparison, and the temporal trends were analyzed via linear regression. Spatial visualization and spatial autocorrelation were conducted by using R 4.4.1, and seasonal pattern identification was based on Seasonal and Trend decomposition Loess. Spearman's correlation (Python 3.12) was used to evaluatethe associations with ozone (O₃), particulate matter PM_2.5（PM₂.₅）, particulate matter PM₁₀（PM₁₀）, and temperature. Geographic weighted regression and Poisson generalized linear model were used to analyze environmental interactions and spatially varying effects.

Results From 2012 to 2020, a total of 127 742 chronic bronchitis death cases were recorded in Chongqing, with the average crude mortality rate declining from 73.81/100000 to 17.41/100000. In men, the rate decreased from 83.67/100000 to 20.23/100000 (P<0.01), and in women, the rate decreased from 63.71 /100000 to 14.58 /100000, The difference was significant (χ²=18.000, P<0.05). There was a seasonal pattern, with annual peaks consistently occurring at the end of the fourth quarter. The spatial distribution was non-random, showing higher risk in southeastern Chongqing. The Spearman correlation analysis identified PM_2.5 and PM₁₀ as significant influencing factors. Poisson generalized linear models revealed that the interactive effects of PM_2.5 with maximum temperature and O₃ with maximum temperature significantly increased risk. Geographic weighted regression model indicated a significant relationships with PM_2.5 concentration and the proportion of population aged ≥60 years, with percentages of 41.61% and 37.56%, respectively. The R² value for the 7 relevant factors was 0.65, with 99.52% of areas showing statistical significance.

Conclusion This study revealed a declining trend in chronic bronchitis cases in Chongqing. The affected people were mainly those aged ≥60 years, and the incidence peak was observed at the end of the fourth quarter. Geographically, the cases were mainly distributed in southeastern Chongqing. Both PM₂.₅ and PM₁₀ showed potential influence on chronic bronchitis patients. Furthermore, a synergistic interaction between PM₁₀ and O₃ significantly increased the disease risk.