Heat Waves and Emergency Department Visits Among the Homeless, San Diego, 2012–2019

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Objectives. To determine the effect of heat waves on emergency department (ED) visits for individuals experiencing homelessness and explore vulnerability factors.

Methods. We used a unique highly detailed data set on sociodemographics of ED visits in San Diego, California, 2012 to 2019. We applied a time-stratified case–crossover design to study the association between various heat wave definitions and ED visits. We compared associations with a similar population not experiencing homelessness using coarsened exact matching.

Results. Of the 24 688 individuals identified as experiencing homelessness who visited an ED, most were younger than 65 years (94%) and of non-Hispanic ethnicity (84%), and 14% indicated the need for a psychiatric consultation. Results indicated a positive association, with the strongest risk of ED visits during daytime (e.g., 99th percentile, 2 days) heat waves (odds ratio = 1.29; 95% confidence interval = 1.02, 1.64). Patients experiencing homelessness who were younger or elderly and who required a psychiatric consultation were particularly vulnerable to heat waves. Odds of ED visits were higher for individuals experiencing homelessness after matching to nonhomeless individuals based on age, gender, and race/ethnicity.

Conclusions. It is important to prioritize individuals experiencing homelessness in heat action plans and consider vulnerability factors to reduce their burden. (Am J Public Health. 2022;112(1):98–106. https://doi.org/10.2105/AJPH.2021.306557)

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Lara Schwarz, MPH , Edward M. Castillo, PhD, MPH , Theodore C. Chan, MD , Jesse J. Brennan, MA , Emily S. Sbiroli, MD , Gabriel Carrasco-Escobar, MPH , Andrew Nguyen, BS , Rachel E. S. Clemesha, PhD , Alexander Gershunov, PhD , and Tarik Benmarhnia, PhD Lara Schwarz and Gabriel Carrasco-Escobar are with the Herbert Wertheim School of Public Health and Longevity Science, University of California, San Diego, La Jolla. Edward M. Castillo, Theodore C. Chan, Jesse J. Brennan, and Emily S. Sbiroli are with the Department of Emergency Medicine, University of California, San Diego. Andrew Nguyen, Rachel E. S. Clemesha, Alexander Gershunov, and Tarik Benmarhnia are with Scripps Institution of Oceanography, University of California, San Diego. “Heat Waves and Emergency Department Visits Among the Homeless, San Diego, 2012–2019”, American Journal of Public Health 112, no. 1 (January 1, 2022): pp. 98-106.


PMID: 34936416