Association between ambient temperature and risk of stroke morbidity and mortality: A systematic review and meta‐analysis

BACKGROUND: Previous studies have suggested that ambient temperature is associated with the morbidity and mortality of stroke although results among these investigations remained unclear. Therefore, the purpose of present meta-analysis was to summarize the evidence of the relationship between ambient temperature and stroke morbidity and mortality. METHODS: A systematic search of the PubMed, Embase, and Web of Science databases was from inception to April 13, 2022. The pooled estimates for heat ambient temperature and cold ambient temperature, which were defined as comparison between extreme hot or cold conditions and the reference or threshold temperature, were calculated utilizing a random-effects model. A total of 20 studies were included in the meta-analysis. RESULTS: The pooled estimated show that the heat ambient temperature was significant associated with 10% (relative risk [RR], 1.10; 95% confidence interval [95%CI]: 1.02-1.18) and 9% (RR, 1.09; 95%CI: 1.02-1.17) increase in the risk of stroke morbidity and mortality, respectively. In addition, the pooled estimated show that the cold ambient temperature was significant associated with 33% (RR, 1.33; 95%CI: 1.17-1.51) and 18% (RR, 1.18; 95%CI: 1.06-1.31) increase in the risk of stroke morbidity and mortality, respectively. CONCLUSION: Integrated epidemiological evidence supports the hypothesis that both heat and cold ambient temperature have positive association with the risk of stroke morbidity and mortality. Targeted measures should be promoted in public health to reduce this risk.