Medical Mondays: ED Utilization for Medicaid Recipients Depends on the Day of the Week, Season, and Holidays

IntroductionThe purpose of this study is to describe and explain the temporal and seasonal trends in ED utilization for a low-income population.MethodsA retrospective analysis of 66,487 ED Medicaid-insured health care claims in 2009 was conducted for 2 Western New York Counties using time-series analysis with autoregressive moving average (ARMA) models.ResultsThe final ARMA (2,0) model indicated an autoregressive structure with up to a 2-day lag. ED volume is lower on weekends than on weekdays, and the highest volumes are on Mondays. Summer and fall seasons demonstrated higher volumes, whereas lower volume outliers were associated with holidays.DiscussionDay of the week was an influential predictor of ED utilization in low-income persons. Season and holidays are also predictors of ED utilization. These calendar-based patterns support the need for ongoing and future emergency leaders’ collaborations in community-based care system redesign to meet the health care access needs of low-income persons.