title: Medical Mondays: ED Utilization for Medicaid Recipients Depends on the Day of the Week, Season, and Holidays.
abstract: The purpose of this study is to describe and explain the temporal and seasonal trends in ED utilization for a low-income population.
  
  
  METHODS
  A 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.
  
  
  RESULTS
  The 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.
  
  
  CONCLUSIONS
  Day 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.
authors.affiliation: Buffalo, NY. Electronic address: jcastner@buffalo.edu.
authors.forename: Jessica
authors.initials: J
authors.lastname: Castner
authors.affiliation: Buffalo, NY.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Buffalo, NY.
authors.forename: Dianne
authors.initials: D
authors.lastname: Loomis
authors.affiliation: Buffalo, NY.
authors.forename: Sharon
authors.initials: S
authors.lastname: Hewner
mesh_terms: D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006693:Holidays / Q000706:statistics & numerical data*; D006801:Humans; D008484:Medicaid; D009518:New York; D012189:Retrospective Studies; D012621:Seasons; D014481:United States
keywords: Emergency department utilization; Medicaid; Primary care; Time series analysis