title: Ten years of frequent users in an urban emergency department.
abstract: BACKGROUND
  The purpose of this study was to determine if differences could be detected in the presentation patterns and admission rates among frequent emergency department users (FEDU) of an urban emergency department over a 10-year period.
  
  
  METHODS
  This was an institutional review board approved, retrospective review of all patients who presented to the ED 5 or more times for 3 distinct time periods: "year 0" 11/98-10/99, "year 5" 11/03- 10/04, and "year 10" 11/08-10/9. FEDU were grouped into those with 5-9, 10-14, 15-19, and ≥ 20 visits per year. Variables analyzed included number of visits, disposition, and insurance status. We performed comparisons using Kolmogorov-Smirnov and chi-square tests. A p<0.05 was considered significant.
  
  
  RESULTS
  We found a a 66% increase in FEDU patients over the decade studied, with a significant increase in both the number of FEDU in each visit frequency category over the 3 time periods (p<0.001), as well as the total number of visits by each group of FEDU (p<0.001). The proportion of FEDU visits for the 5-9 group resulting in admission increased from 25.9% to 29% from year 0 to year 10 (p<0.001), but not for the other visit groups. In comparing admission rates between FEDU groups, the admission rate for the 5-9 group was significantly higher than the ≥ 20 group for the year 5 time period (p<0.001) and the year 10 time period (p<0.001) and showed a similar trend, but not significant, at year 0 (p=0.052). The overall hospital admission rate for emergency patients over the same time span remained stable at 22-24%. The overall proportion of uninsured FEDU was stable over the decade studied, while the uninsured rate for the overall ED population for the same time periods increased.
  
  
  CONCLUSIONS
  The results demonstrate the FEDU population is not a homogeneous group of patients. Increased attention to differences among FEDU groups is necessary in order to plan more effective interventions.
authors.affiliation: Henry Ford Health System, Department of Emergency Medicine, Detroit, Michigan.
authors.forename: Gerard B
authors.initials: GB
authors.lastname: Martin
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Stokes-Buzzelli
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Peltzer-Jones
authors.forename: Lonni R
authors.initials: LR
authors.lastname: Schultz