Disparities in the impact of heat wave definitions on emergency department visits during the first year of life among preterm and full-term infants in California

Anaïs Teyton; Allan Ndovu; Rebecca J Baer; Gretchen Bandoli; Tarik Benmarhnia

doi:10.1016/j.envres.2024.118299

Disparities in the impact of heat wave definitions on emergency department visits during the first year of life among preterm and full-term infants in California

Environ Res. 2024 May 1:248:118299. doi: 10.1016/j.envres.2024.118299. Epub 2024 Jan 23.

Authors

Anaïs Teyton¹, Allan Ndovu², Rebecca J Baer³, Gretchen Bandoli⁴, Tarik Benmarhnia⁵

Affiliations

¹ Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA; School of Public Health, San Diego State University, 5500 Campanile Dr, San Diego, CA, 92182, USA; Scripps Institution of Oceanography, University of California, San Diego, 8885, Biological Grade, La Jolla, CA, 92037, USA. Electronic address: ateyton@ucsd.edu.
² University of California San Francisco School of Medicine, 533 Parnassus Ave, San Francisco, CA, 94143, USA.
³ California Preterm Birth Initiative, University of California, San Francisco, 490 Illinois Street, Flr. 9 Box 2930, San Francisco, CA, 94143, USA; Department of Pediatrics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
⁴ Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA; Department of Pediatrics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
⁵ Scripps Institution of Oceanography, University of California, San Diego, 8885, Biological Grade, La Jolla, CA, 92037, USA.

PMID: 38272297
DOI: 10.1016/j.envres.2024.118299

Abstract

Introduction: Heat waves will be aggravated due to climate change, making this a critical public health threat. However, heat wave definitions to activate alert systems can be ambiguous, highlighting the need to assess a range of definitions to identify those that contribute to the most adverse health outcomes. Additionally, children are highly susceptible to the impacts of heat waves, especially infants, despite the lack of focus on this subpopulation. We aimed to assess the relationship between 30 heat wave definitions and the first all-cause emergency department (ED) visits for California infants. We also examined modification of this relationship by preterm birth status and demographic characteristics to identify possible health disparities.

Methods: Live-born, singleton deliveries from the Study of Outcomes in Mothers and Infants born in 2014-2018 were included. Thirty heat wave definitions were assessed based on temperature metrics (minimum/maximum temperatures), thresholds (90th; 92.5th; 95th; 97.5th; 99th percentiles), and duration (1-; 2-; 3-days). A time-stratified case-crossover design assessed heat wave impacts on ED visits using infants with a warm season ED visit (May-October) within the first year of life (n = 228,250). Effect modification by preterm birth status, age, sex, race/ethnicity, education, and delivery payment type was also investigated.

Results: Infants demonstrated increased risk of an ED visit with exposure to all heat definitions. The 3-day minimum temperature 99th percentile definition had the highest adjusted odds ratio (AOR: 1.14; 95% CI: 1.05-1.23) for the total population. Term infants were more affected by some heat waves than preterm infants. Effect modification was additionally identified, such as by maternal education.

Discussion: This study provides insight on the heat wave definitions that lead to adverse health outcomes and the identification of the most susceptible infants to these impacts, which has implications on heat-related interventions.

Keywords: Children's health; Climate change; Emergency department visits; Extreme heat; Heat wave.

MeSH terms

California
Emergency Room Visits
Emergency Service, Hospital
Female
Hot Temperature*
Humans
Infant, Newborn
Infant, Premature
Male
Premature Birth* / epidemiology