Objectives: Although the relationship between urbanization and influenza has received increasing attention, previous studies have often examined this relationship based on single indicators, neglecting the multi-dimensions of urban development and their integrated impact on influenza incidence in neighboring cities.

Methods: A multidimensional urbanization evaluation framework was developed based on social, economic, and ecological dimensions to comprehensively assess urbanization. Then, we analyzed the impact of urbanization development on influenza incidence within and across cities using Bayesian spatiotemporal models and spatial Durbin models. Regional heterogeneity analysis was performed to investigate the impact of urbanization on influenza incidence within cities.

Results: From 2014 to 2019, there were 5,062,254 influenza cases in 283 prefecture-level cities in China. Each standard deviation increment in comprehensive, social, and economic indexes of urbanization was associated with a 14.9% (95% CI: 6.1%, 24.3%), 9.9% (95% CI: 3.5%, 16.3%), and 13.4% (95% CI: 4.5%, 23.7%) increase in influenza incidence, respectively. The effects of urban development on influenza incidence varied significantly across regions, with the greatest impact found in southern China. Additionally, a significant positive spatial spillover effect of urbanization was observed on influenza incidence in surrounding cities.

Conclusions: Urbanization and its various dimensions were linked to increased risk of local influenza incidence, which also showed substantial positive spatial spillover effect to surrounding areas. During the rapid urbanization process in China, local governments should prioritize equity and accessibility in healthcare services and strengthen the coordinated prevention and control of influenza epidemics across cities.