The Effects of High Heat on Emergency Department Visits for Accidental Injuries Open Access

Rodriguez, Andrea (Spring 2021)

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Introduction: Climate change has resulted in an increase of the global mean temperature and increase in the frequency of high heat events. The effects of high heat have been examined for mortality and specific morbidity conditions, but few studies have examined the effects of high heat and the risk of injury or injury causes. The aim of this study is to estimate the effects of high heat on the risk of emergency department visits for accidental injuries, including an assessment of injury causes, in Los Angeles, California during the warm season, May- September, 2005 – 2015.


Methods: Over-dispersed Poisson log-linear time-series models were run to estimate associations of current day (lag day 0) daily maximum temperature and ED visit counts for thirteen accidental injury categories. Models controlled for mean dew point temperature, day of the week, holidays, hospital-specific indicators, and long-term time trends. The estimates for the nonlinear relationship were calculated for the 1st to the 99th percentile of maximum daily temperature, using the 25th percentile temperature (25 C) as the reference temperature. Secondary analyses considered models stratified by age group, and the assessment of lag structures up to lag day 3. Sensitivity analyses were conducted to control for the presence of precipitation, high amounts of precipitation, and air pollution.


Results: Significant nonlinear associations between daily maximum temperature and injury ED visits were observed for seven of the thirteen injury categories: natural and environmental factors, cuts/pierce, drownings, machinery, injuries struck by or against, falls, and bicycle injuries. Most of the seven injury outcomes had the strongest nonlinear relationship on lag day 0. Overall, for most injury categories, associations with temperature were similar across age groups. Controlling for the presence of rain and high amounts of rain did not substantially change the nonlinear relationships observed between temperature at the various accidental injury outcomes. However, pollution did affect the observed associations for all of the seven accidental injury outcomes


Conclusion: These findings expand the literature on the effects of high temperatures on human health, and specifically illustrate the impacts of heat on healthcare utilization for accidental injuries.

Table of Contents

Introduction (1)

Methods (2)

Results (6)

Discussion (18)

Conclusion (22)

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