Pre hospital emergency medical dispatches following heat waves: A systematic review study and meta-analysis

Abstract

Given that climate change is a global phenomenon influencing various aspects of health, this study aimed to conduct a systematic review and meta-analysis of the effects of heat waves on pre-hospital emergency medical dispatches (EMDs) worldwide. This study was conducted in accordance with the PRISMA guidelines. Relevant English-language studies were searched using specific keywords related to “heat wave, EMDs, and health” in reputable databases such as Scopus, PubMed, and WoS from the inception of each database until December 2024. The selection of related studies was based on screening the title, abstract, and full text. Two researchers independently identified studies according to predefined inclusion and exclusion criteria. Out of 494 identified studies, 20 papers were evaluated. A random-effects model or a fixed-effects model was chosen based on the heterogeneity criterion. Publication bias was assessed using a funnel plot and Egger's test. The overall results of the meta-analysis indicated that heat waves, considering the 99th and 95th percentiles of temperature, are significantly associated with an increase in EMDs, with RRs of 1.11 (95% CI: 1.06, 1.15) and 1.09 (95% CI: 1.05, 1.13), respectively. Additionally, heat waves significantly affect the number of EMDs for middle-aged and elderly individuals, with RRs of 1.48 (95% CI: 1.18, 1.78) and 1.19 (95% CI: 1.14, 1.24), respectively. The overall results of the meta-analysis indicated that heat waves, considering the 95th and 99th percentiles of temperature, are significantly associated with an increase in EMDs due to cardiovascular diseases, with RRs of 1.054 (95% CI: 1.009, 1.100) and 1.038 (95% CI: 1.000, 1.075), respectively. Given the increasing trend of global warming and the subsequent rise in the incidence and intensity of heat waves, the pre-hospital medical emergency system must be prepared to respond appropriately to such events.