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Updated: Jun 26, 2026
An R-Based Landscape Validation of a Competing Risk Model
Published on: September 16, 2022
Temperature variability and mortality risk: distinguishing intraday and interday effects and quantifying the
Jiaqi Huang1, Dan Kuang1, Jingwen Sun1
1Chengdu Center for Disease Control and Prevention (Chengdu Institute of Health Supervision), Chengdu, Sichuan, China.
Background:
With the ongoing global climate change, the adverse health impacts of extreme weather and climate events such as heatwaves and cold spells have been widely investigated, while the effects of temperature variability (TV) remain insufficiently explored, and the differential impacts of intraday TV and interday TV are largely unidentified.
Objectives:
To investigate the associations between three TV indices (total TV, intraday TV, interday TV) and mortality, and to quantify the TV-attributable mortality burden in Chengdu.
Methods:
Daily meteorological and mortality data in Chengdu from 2015 to 2024 were collected. The three TV indices were derived from different forms of standard deviations of daily minimum/maximum/mean temperatures. Distributed lag non-linear models (DLNMs) were used to assess the associations between TV indices and mortality. Comprehensive subgroup analyses stratified by cause of death, gender, age group, and season were conducted to identify vulnerable populations. The mortality burden attributable to TV was quantified using attributable numbers of deaths (AN) and attributable fractions (AF).
Results:
Total TV and intraday TV were significantly positively associated with daily mortality in Chengdu, while interday TV showed a negative association. For each interquartile range (IQR) increase in total TV, intraday TV and interday TV, the corresponding all-cause mortality risk increased by 1.4% (0.5, 2.3%), 2.9% (2.0, 3.8%), and -1.7% (-2.3, -1.1%), respectively. The AN of all-cause deaths attributable to intraday TV was 27,186 (18,527, 35,767), and the AFs of intraday TV for all-cause, cardiovascular disease-related, and respiratory disease-related deaths were 2.82% (1.92, 3.71%), 2.83% (1.68, 3.97%), 5.19% (3.80, 6.56%), respectively. Subgroup analyses identified deaths due to respiratory diseases, females, and individuals aged ≥65 years as vulnerable populations. Additionally, the adverse effect of intraday TV was more pronounced during the cold seasons.
Conclusion:
This study suggested that short-term temperature variations elevate the mortality risk in Chengdu, with intraday TV as the primary driver of the increased mortality risk. These findings enrich evidence on TV-related health impacts, highlight the need to distinguish intraday and interday TV in research and practice, and support local climate-health adaptation and intervention strategies.