Hospitalizations for heat-stress illness varies between rural and urban areas: an analysis of Illinois data, 1987–2014

Abstract

BackgroundThe disease burden due to heat-stress illness (HSI), which can result in significant morbidity and mortality, is expected to increase as the climate continues to warm. In the United States (U.S.) much of what is known about HSI epidemiology is from analyses of urban heat waves. There is limited research addressing whether HSI hospitalization risk varies between urban and rural areas, nor is much known about additional diagnoses of patients hospitalized for HSI.MethodsHospitalizations in Illinois for HSI (ICD-9-CM codes 992.x or E900) in the months of May through September from 1987 to 2014 (n = 8667) were examined. Age-adjusted mean monthly hospitalization rates were calculated for each county using U.S. Census population data. Counties were categorized into five urban-rural strata using Rural Urban Continuum Codes (RUCC) (RUCC1, most urbanized to RUCC5, thinly populated). Average maximum monthly temperature (°C) was calculated for each county using daily data. Multi-level linear regression models were used, with county as the fixed effect and temperature as random effect, to model monthly hospitalization rates, adjusting for the percent of county population below the poverty line, percent of population that is Non-Hispanic Black, and percent of the population that is Hispanic. All analyses were stratified by county RUCC. Additional diagnoses of patients hospitalized for HSI and charges for hospitalization were summarized.ResultsHighest rates of HSI hospitalizations were seen in the most rural, thinly populated stratum (mean annual summer hospitalization rate of 1.16 hospitalizations per 100,000 population in the thinly populated strata vs. 0.45 per 100,000 in the metropolitan urban strata). A one-degree Celsius increase in maximum monthly average temperature was associated with a 0.34 increase in HSI hospitalization rate per 100,000 population in the thinly populated counties compared with 0.02 per 100,000 in highly urbanized counties. The most common additional diagnoses of patients hospitalized with HSI were dehydration, electrolyte abnormalities, and acute renal disorders. Total and mean hospital charges for HSI cases were $167.7 million and $20,500 (in 2014 US dollars).ConclusionElevated temperatures appear to have different impacts on HSI hospitalization rates as function of urbanization. The most rural and the most urbanized counties of Illinois had the largest increases in monthly hospitalization rates for HSI per unit increase in the average monthly maximum temperature. This suggests that vulnerability of communities to heat is complex and strategies to reduce HSI may need to be tailored to the degree of urbanization of a county.

Health effects from heat waves in France: an economic evaluation

“…Most of the studies only included direct impacts in the economic valuation: mortality [ 40 , 54 , 56 – 68 ], hospital admissions or outpatient visits (emergency room visits, hospitalizations, outpatient consultations, etc.) [ 38 , 40 , 54 , 56 – 58 , 62 – 64 , 67 , 69 – 72 ] or the loss of production associated with morbidity [ 40 , 56 , 58 , 63 , 66 , 71 ]. Fourteen studies built a model to obtain the number of hospital admissions or outpatient visits associated with heat waves [ 40 , 54 , 56 – 64 , 69 , 71 , 72 ], while the others did not specify their method of calculation.…”

“…[ 38 , 40 , 54 , 56 – 58 , 62 – 64 , 67 , 69 – 72 ] or the loss of production associated with morbidity [ 40 , 56 , 58 , 63 , 66 , 71 ]. Fourteen studies built a model to obtain the number of hospital admissions or outpatient visits associated with heat waves [ 40 , 54 , 56 – 64 , 69 , 71 , 72 ], while the others did not specify their method of calculation. All the studies found the estimated health costs of heat waves to be significant.…”

Factors That Influence Climate Change-Related Mortality in the United States: An Integrative Review

“…Like rural areas, even smaller more spread-out cities lack heat adaptations and warning systems as the risk of heat exposure is underestimated when compared with more densely populated urban centers [78]. The least populated areas of Illinois had average annual hospitalization rate due to heat stress of 1.16 hospitalizations per 100,000 people, while metropolitan areas had 0.45 hospitalizations per 100,000 people [79].…”

Facing the urban overheating: Recent developments. Mitigation potential and sensitivity of the main technologies

“…Urban citizens should be better educated to counteract urban overheating, especially during heat waves. They should indeed effectively operate passive cooling strategies, given the well-known role of UHI and heat waves on population health diseases risk (Huber, Ibarreta, & Frieler, 2017;Jagai, Grossman, Navon, Sambanis, & Dorevitch, 2017;Schuster, Honold, Lauf, & Lakes, 2017;Youngsteadt, Ernst, Dunn, & Frank, 2017).…”