Seasonal variation in the incidence of in-hospital cardiac arrest

Background: Seasonal variation in cardiovascular outcomes, including out-of-hospital cardiac arrest, has been described. Objectives: This study aimed to investigate seasonal differences in the incidence of in-hospital cardiac arrest (IHCA) and associated mortality. Methods: Using National Inpatient Sample data from 2005 to 2019, we determined the incidence of IHCA in 4 seasons. The primary objective was to evaluate overall seasonal trends in the incidence of IHCA and trends stratified by sex, age, and region. The secondary aim was to determine common causes of admission that led to IHCA, differences in those with shockable vs nonshockable IHCA, independent predictors of IHCA, and seasonal variation in IHCA-related in-hospital mortality and length of stay. Results: A consistent winter peak was observed in the incidence of IHCA in both male and female patients over the years in all age groups except young ( Conclusions: Improving insights into factors that influence the higher IHCA event rate during winter may help with proper resource allocation, development of strategies for early recognition of patients vulnerable to IHCA, and closer monitoring and optimization of care to prevent IHCA and improve outcomes