Urban-rural disparity of low-temperature-related mortality from northernmost to southernmost regions in China.

Unresolved issues still exist regarding urban-rural disparity of temperature-related mortality among different regions. We collected daily all-cause mortality data from 7,439,777 individuals in 300 counties across six temperature zones in China, ranging from the coldest to hottest regions, from 2017 to 2021. Additionally, we obtained the daily average temperature, relative humidity, and concentrations of PM_2.5 and O₃ in these regions during the same period. Distributed lag non-linear model and meta-regression were used to analyse the data; the fraction of mortality attributable to low temperature was calculated. The results showed that there is a significant difference in the attributable fraction of low temperature between urban and rural areas in temperate regions (North China); this difference was relatively small in subtropical and tropical regions (South China), indicating that man-made protective facilities were more reliable in resisting the low temperature than people's physiological adaptation. Central heating in urban areas in temperate regions resulted in a lower attributable fraction of low temperature at each age group, central heating was also necessary in the northern and middle subtropical regions to achieve the highest cold burden.