392 Seasonal Presentation Patterns for Congestive Heart Failure Within a Cohort of Southern Coastal US Emergency Department Patients

Abstract

Seasonal differences in disease occurrence may inform adjustments to therapeutic regimens. A previous study of emergency department (ED) visits in New Jersey for congestive heart failure (CHF), showed a marked increase in the colder months (35% higher in December compared to August). The authors speculated that this was due in part to increased catecholamine release in response to cold weather. We hypothesized that less harsh winter temperatures in the southern coastal U.S. region might blunt this effect, resulting in a smaller winter-summer difference than the authors observed in New Jersey. We conducted a retrospective cohort study utilizing data from 287 emergency departments within the southern coastal U.S. region. Patients with a primary diagnosis of CHF or pulmonary edema from 01/01/07 to 08/05/19 were included. We aggregated data electronically from medical records and tabulated the number of visits by month, correcting for the length of month. We utilized chi-square to assess for non-uniformity in distribution of visits by month. We calculated the relative difference between the month with the most and least visits along with the 95% confidence interval (CI). There were 285,561 visits for CHF during the study period. Of these, 52% were female and the mean age was 69 +/-16 years. Chi-square rejected uniformity for CHF visits by month (p<0.0001). There were more CHF visits in the colder months. There were 34% more visits in January the peak month versus August the month with the least (95% CI 32% to 36%, p < 0.0001). Contrary to our hypothesis we found a similar winter-summer difference in the southern coastal US region as that in New Jersey. It is unclear why this difference persists despite the fact that winters in the southern coastal region are less harsh than in New Jersey.