Extreme heat associated with increased asthma hospital visits
Key takeaways:
- Extreme daytime heat events were associated with higher odds of children’s asthma-related hospital visits.
- Longer durations of the heat events doubled the risk of a hospital visit.
SAN DIEGO — High heat events and extreme temperatures that lasted several days showed an increase in asthma-related hospital visits, according to a presentation at the American Thoracic Society International Conference.
Previous studies examining hospitalizations and ED visits showed conflicting results with few studies focusing on asthma exacerbations, Morgan Ye MPH, research data analyst, department of medicine and epidemiology and biostatistics, University of California, San Francisco (UCSF), and colleagues wrote.
“Many other studies have focused on respiratory hospitalizations and not hospitalizations for asthma specifically and have not included or had a focus on children,” Ye told Healio.
The study focused on children receiving care at an urban pediatric health center in California that caters to medically underserved populations.
“The San Francisco Bay Area and California at large are unique areas of interest because it is considered a coastal region with less prevalence of cooling units,” Ye said. “While temperatures may not reach the extremes experienced in other parts of the country, our study demonstrates that even ‘milder’ extreme heat temperatures may significantly impact health.”
Electronic health record data from 2017 to 2020 from the UCSF Benioff’s Children Hospital Oakland were used in the study. This included data on asthma-related hospital visits and patient demographics including patient zip codes.
Heat event and temperature data were derived from the PRISM Climate Group of Oregon State University, specifically looking at daily maximum and minimum temperatures. Analysis was performed from June to September of each year.
The study used 18 heat wave definitions including temperatures that exceeded the 99th, 97.5th, and 95th percentiles of temperature distribution across a period from 1 to 3 days.
“We found that extreme heat events were associated with increased asthma hospital visits,” Ye said. “Specifically, persistent extreme temperatures (ie., where the temperature is high for several days in a row) were shown to increase the risk of asthma hospital visits.”
Daytime heatwaves were significantly associated with an increased chance of asthma-related hospital visits (OR = 1.21; 95% CI, 1.01-1.45 and OR = 1.79; 95% CI, 1.07-2.99 for 1 day, 95th percentile and 3 day, 99th percentile, respectively).
When these results were stratified by the Bay Area and Central California, there was a positive association in the Bay Area (OR = 1.83; 95% CI, 1.08-3.11), but no associations for Central California. No associations were observed for nighttime heat waves.
Authors highlight that these findings can lead to more equitable health outcomes and be used to make informed actions in alleviating health-related stress during heat waves for children in vulnerable populations.
“Understanding the impacts of climate-sensitive events such as extreme heat on a population is the key to reducing the burden of disease due to climate change,” Ye said. “As we continue to see global temperatures rise due to human-generated climate change, we can expect a rise in health-related issues as we observe longer, more frequent and severe heat waves.”
Ye further explained that this study’s findings aim to reduce racial and ethnic disparities observed in climate-sensitive events.
“Children and families with lower adaptation capacity will experience most of the burden,” Ye said. “Therefore, it is important to obtain a better understanding of these heat-associated health risks and susceptible populations for future surveillance and targeted interventions.”
Furthering equity in asthma care can also be done through public health policy and education, according to study authors.
“Targeted public health messaging for climate-susceptible populations that include helpful tips and resources can help individuals avoid unhealthy exposures and to prepare for and adapt to future climate change,” Ye explained. “At a structural and policy level, advocating for green infrastructure, shading to combat health island effect (common in high density urban areas comparable to our study population area of study), and increasing access to proper ventilation and cooling systems are mechanisms to help safeguard communities against the health risks of extreme heat.”