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Extreme Weather Events Tied to Increased Mortality and Emergency Department Activity

A Mass General Brigham study reveals that emergency department visits and death are heightened weeks after major climate-driven extreme weather events — highlighting the long-lasting impacts these events may have on health and infrastructure.

Renee Salas, MD, MS, MPH

Climate change is increasing the frequency and intensity of severe weather events, which may particularly endanger vulnerable populations such as the elderly. Researchers from Mass General Brigham and colleagues examined how weather disasters between 2011 and 2016 influenced healthcare delivery and mortality among Medicare beneficiaries in affected counties, finding that one week after major weather events, emergency department (ED) use and mortality remained elevated by 1.22% and 1.4%, respectively, from pre-disaster levels. Importantly, this study also found that deaths remained elevated for as much as six weeks. Results are published in Nature Medicine.

Researchers from Massachusetts General Hospital and Brigham and Women’s Hospital, founding members of the Mass General Brigham healthcare system, collaborated on the study. Identifying events from the National Oceanographic and Atmospheric Administration (NOAA)’s National Centers for Environmental Information (NCEI), the team analyzed acute disasters such as floods, storms and hurricanes that caused $1 billion or more in damages. Severe storms, compared to other disasters, were associated with the highest mortality rates that persisted for six weeks. Counties with the greatest economic losses were found to have two to four times higher mortality rates — and higher ED usage — compared to all affected counties, highlighting how infrastructure destruction, such as power outages and transportation challenges, may compound both economic and healthcare tolls.

“Taken together, these findings suggest that the biggest weather disasters have broad and long-lasting impacts on health emergencies and deaths among those who have Medicare,” said lead author Renee Salas, MD, MS, MPH, of the Department of Emergency Medicine at Massachusetts General Hospital. “Tracking these outcomes is important to better protect patients and communities — and to strengthen our health systems.”

Authorship:  Mass General Brigham affiliated co-authors include E. John Orav (BWH). Additional co-authors include Laura G. Burke, Jessica Phelan, Gregory A. Wellenius, and Ashish K. Jha.

Disclosures: Salas reports no disclosures. Additional author disclosures are included in the article.

Funding: This research was funded by the Burke Global Health Fellowship at the Harvard Global Health Institute, the Clinician-Teacher Development Award at the Center for Diversity and Inclusion at Massachusetts General Hospital, and the Yerby Fellowship at the Harvard T.H. Chan School of Public Health. A full list of funding to individual authors is included in the article.

Paper cited: Salas RN et al. “Impact of extreme weather events on healthcare utilization and mortality in the United States” Nature Medicine DOI: 10.1038/s41591-024-02833-x.

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