Effects of heat on ambulance call-outs

Abstract

PDS 66: Climate change, Exhibition Hall (PDS), Ground floor, August 28, 2019, 1:30 PM - 3:00 PM Background/Aim: Few multi-city studies on heat and emergency health outcomes have been conducted in Asia. This study aimed to examine the associations between high temperature and ambulance call-outs (ACOs) in ten cities in China to identify vulnerable populations and explore the regional differences and possible causes. Methods: Daily air pollution, meteorological data and ACOs were collected from ten cities during 2014-2017. We first applied a semi-parametric generalized additive model with a Poisson distribution to analyze the city-specific associations of daily maximum temperature and number of ACOs during June to August after controlling for covariates including outdoor air pollution. Then pooled these effect estimates using meta-analysis at the national level, and finally further explore the heterogeneity at regional level using subgroup analysis stratified by latitude and per capita disposable income (PCDI). Gender and age-specific associations were estimated to identify vulnerable sub-populations. Results: Strong associations between daily maximum temperature and ACOs were observed in multiple cities, with increases of 0.7% (0.2%, 1.1%) to 2.7% (2.0%, 3.5%) in daily overall ACOs with each 1°C increment in the daily maximum temperature. Slightly stronger pooled temperature-ACOs association was detected in males compared to females. Adults, especially the population aged 18-44 years, reported significant heat-ACOs association (pooled RR=1.017, 95%CI: 1.011–1.022), and the younger adults with the higher risks. Generally, the south and central regions seemed to have higher risks than north region in China and the regional vulnerability appeared to be related to the combination of latitude, climate and PCDI. Conclusions: Population and region-specific significant associations between ACOs and high temperature were observed in multiple cities, suggesting combined impacts of climate and economy on the emergency health situations against high temperature, deserves further larger multi-city studies as evidence for relevant national and regional public health strategies and early warning system.