Home Medication and Heat-Sensitive Emergency Department Visits in Atlanta

BACKGROUND AND AIM: Several classes of drugs are known to affect heat tolerance by impairing sweat production, thermoregulation and thirst sensation. However, few population-based studies have considered the influence of prescribed medications on heat-related morbidity. This study aims to evaluate the hypothesis that patients on certain medications are more vulnerable to short-term high ambient temperatures. METHODS: We obtained electronic health records of emergency department (ED) visits from Emory Healthcare hospitals during May to September for the period 2016 to 2018. Patients reported current prescriptions at ED intake and we categorized medications into 12 classes of interest. Daily meteorology from the Daymet 1km product was linked to patient residential ZIP codes. Using a case-crossover design, we examined associations between maximum temperature averaged over lag 0-2 days and ED visits for two heat-sensitive ED outcomes: acute kidney injury (AKI) and fluid and electrolyte imbalance (FEI). Effects of temperature were modeled non-linearly and effect modification by medication type was examined in age-matched stratified analyses. RESULTS: There were 11,423 AKI and 22,506 FEI ED visits during the study period. For AKI, we found stronger associations with temperature (comparing 34 ⁰C to 29 ⁰C) among patients with prescriptions of antipsychotics (OR = 1.88, 95% CI: 1.17-3.01) and diuretics (OR = 1.32, 95% CI: 1.04-1.70) compared to patients without any reported medication. For FEI, stronger associations were observed among patients with prescriptions of beta-adrenergic blocking agents (OR = 1.20, 95% CI: 1.00-1.46) and diuretics (OR = 1.33, 95% CI: 1.07-1.64). No effect modification was observed for several common medication types, including ACE inhibitors, anticonvulsants, antihistamines, calcium channel blockers and statins. CONCLUSIONS: We identified several subpopulations more vulnerable to short-term heat exposures based on self-reported home medications. These results are important for the development of more targeted strategies to reduce heat-related morbidity. KEYWORDS: Heat, Medication, Morbidity