Study: Variation in One-Year Mortality Following Severe Weather Exposure Among Older Americans by Chronic Health Condition and Sociodemographic Status (DOI: 10.1111/jgs.70237)
Older adults who were exposed to heavy rainfall after Hurricane Harvey in 2017 faced a 3% increase in the risk of death within the following year, a new University of Michigan study found.
"These findings add to the evidence that disasters don't just cause short-term disruptions. They expose and magnify the underlying fragilities in our health systems," said lead author Sue Anne Bell, U-M associate professor of nursing. "For older adults who rely on regular and consistent access to health care, even a temporary disruption to needed care can have lasting consequences."
The study, appearing in the Journal of the American Geriatrics Society and funded by the National Institute on Aging, provides new evidence that severe weather events have long-term health consequences for vulnerable older adults. Identifying populations at heightened risk for disasters can inform targeted preparedness and health care interventions to reduce mortality disparities, Bell said.
Bell and colleagues from U-M and the University of Illinois Chicago examined Medicare claims data for nearly 1.8 million beneficiaries aged 65 and older in Texas and Louisiana in the year before and after Hurricane Harvey. They used historical weather data to construct a four-day measure of cumulative rainfall and the primary severe weather caused by Hurricane Harvey, and identified vulnerable subgroups based on five chronic health conditions requiring regular health care access and sociodemographic factors.
Key findings:
- Mortality risk was highest among those with chronic health conditions requiring regular care, including chronic kidney disease and Alzheimer's disease and related dementias.
- The largest number of attributed deaths was among the Alzheimer's disease and related dementias population: an estimated 1,245 deaths in the year following Hurricane Harvey (5% higher risk of death).
- Chronic kidney disease patients had 423 attributable deaths (4% higher risk of death).
- Patients with diabetes also face a 4% higher risk of death.
- Black and Hispanic/Latino populations experienced 6% and 13% higher mortality risks, respectively, than other groups, highlighting disparities in vulnerability to disasters.
While the immediate effect of exposure to severe weather from hurricanes on mortality is well-documented, it is unknown whether mortality in the year following exposure to severe weather differs across older Americans with specific vulnerable characteristics. The study sought to determine whether the association between exposure to high rain and one-year mortality differs across vulnerable subgroups of older adults.
Bell and colleagues found that the official death toll of 103 lives underestimates the disaster's reach. According to their research, an estimated 3,738 additional deaths among older adults can be attributed to the one-year period following the storm, although that figure is unadjusted.
In 2023, the United States experienced 28 separate weather and climate disasters, with total damages nearing $93 billion and 492 reported deaths. There is a need to understand disaster-associated mortality from these events, particularly related to hurricane exposure among older adults given their high population growth and concentration in the 18 hurricane-prone Atlantic and Gulf Coast states.
The research was supported by the National Institute on Aging of the National Institutes of Health (study award RF1AG083768). The content is solely the responsibility of the authors and does not necessarily reflect the views of the NIH.
Co-authors include: Melissa Fiffer, Joshua Tootoo, Ryan Zomorrodi, Aaron Lilienfeld and Marie Lynn Miranda of the University of Illinois Chicago, and Jonathan Martindale, Julie Bynum and Matthew Davis of the University of Michigan.
