Heat-Related Illness Diagnoses Among Private Payer Members Are Increasing

Privately-insured Americans experienced higher rates of heat-related illness diagnoses in 2021 compared to 2016, in some cases a more than 37 percent increase, according to a report from FAIR Health.

“The Centers for Disease Control and Prevention has identified projected increases in extreme summer heat as one source of adverse health impacts from climate change. However, systematic, national data on trends in heat-related illnesses in the United States have been lacking,” the report began.

FAIR Health used private healthcare claims records to assess trends in heat-related illnesses among privately-insured Americans. They compared each month from May to September of 2016 with the corresponding month in 2017 through 2021 for three major heat-related conditions: heat stress, heat exhaustion, and heatstroke.

For heat stress, the researchers discovered that every month in 2021 had higher rates of heat-related illnesses than the same month in 2016.

The month with the smallest growth in heat stress diagnoses was August, in which the prevalence of these conditions rose 6.7 percent from 2016 to 2021. The month with the highest increase was May, which saw a 37.8 percent increase from the rates in 2016 compared to 2021.

In May, June, and July, the year with the highest level of heat stress diagnoses among the privately-insured was 2021. August’s highest rates were in 2018 and 2020, while September’s highest rate was in 2018.

Certain patient populations had higher rates of heat stress diagnoses. Age and gender could each present risk factors. Individuals ages 65 and over were especially at risk of heat stress. Nearly two percent of individuals in this age bracket experienced heat stress, which was more than twice the rate of individuals in the next highest bracket (ages 55 to 64).

Additionally, male privately-insured members were slightly more likely to experience heat stress. According to the FAIR Health data—which is corroborated by previous findings on heat-related illnesses—men are more likely to experience heat stress than women (52 percent compared to 48 percent, respectively). However, among younger member populations, females were more likely to receive a heat stress diagnosis.

Rates of heat exhaustion diagnoses were not as staggering as heat stress diagnoses, but demonstrated an overall upward trend nonetheless. June saw the highest increase between 2016 and 2021 rates with a 52.5 percent increase, while September saw a 25.9 percent increase between the first and last years of the study timeframe.

Once again, older adults with private healthcare coverage were more likely to be diagnosed with heat exhaustion and males were overwhelmingly more likely to receive a heat exhaustion diagnosis. Nearly two-thirds of heat exhaustion diagnoses were among males (64 percent). This overall trend remained true regardless of age.

Finally, heatstroke demonstrated the most varied trends. The year with the highest rate of diagnoses differed based on the month. Still, the overarching trend was an increase. September saw the highest increase from 2016 to 2021 at 40.1 percent, and August saw the lowest increase at just 12.0 percent.

Older adults with private payer coverage were especially susceptible to heatstroke. Those ages 65 and older were 2.54 times more likely to receive a heatstroke diagnosis compared to the next highest age bracket (55 to 64).

Once again, privately-insured males were more likely to experience heatstroke than females, with 64 percent receiving a heatstroke diagnosis. This held true across age brackets.

“The findings in this report have implications for all healthcare stakeholders concerned with heat-related illnesses, including patients, providers, payors and policy makers,” the report concluded.

“FAIR Health hopes that these findings will also be starting points for further research on heat-related illnesses, as global temperatures increase and such illnesses become more prevalent.”

As healthcare claims for heat-related illnesses rise, payers will be forced to adapt their programs and potentially add new benefits that serve the affected patient population.

In August 2022, Cigna responded to the heat threat by expanding its Medicare Advantage transportation benefit. Under the improved benefit, members could receive coverage for transportation to cooler locations.

Payers have also taken steps to improve access to care and reduce social determinants of health barriers for those who are most vulnerable to weather conditions, specifically the homeless population. For example, one payer in California funded a street medicine program that brings care to individuals living on the streets of Orange County, California. Homelessness is a condition that employers are starting to take more responsibility for as well.