The shift of heat-related respiratory mortality from 2005 to 2019 in China and its socioeconomic determinants

While extensive research has examined acute mortality risks associated with heat exposure, emerging evidence indicates a paradoxical decline in heat-attributable mortality across developed nations. Yet critical knowledge gaps persist regarding this epidemiological transition in China. Our study collected daily respiratory mortality data from 2,219 districts/counties in 31 provinces, China during 2005–2019. We investigated the minimum mortality temperature (MMT) experienced an increment of 0.124℃ per year from 2005 to 2019 ( P = 0.038), while the excess risk (ER) associated with extreme heat declined from 9.46% (95% Confidence Interval (CI): 4.81–14.32%) in 2005–2007 to 3.51% (95% CI: 2.12–4.92%) in 2017–2019, representing a 62.88% (95% CI: 55.31–69.99%) reduction. Similarly, the attributable fraction (AF) also decreased from 1.26% (95% CI: 0.57–1.92%) to 0.38% (95% CI: 0.21–0.55%), marking a 69.84% (95% CI: 48.91–89.24%) decrease. Stratified analyses revealed the mortality burdens decreases were more pronounced among males, individuals 0–64 years, southern China, and patients with chronic obstructive pulmonary disease (COPD). Urbanization rate, the prevalence of air conditioning, and green space were top three socioeconomic factors driving this temporal shift. Our analysis reveals an attenuation of heat-associated respiratory mortality between 2005–2019, concurrent with rising MMT exhibiting pronounced population and spatial disparities. It underscores the critical role of adaptive capacity in mitigating climate change-related health burdens, informing targeted public health strategies.