title: Epidemiologic analysis of an urban, public emergency department's frequent users.
abstract: OBJECTIVE
  To determine how the demographic, clinical, and utilization characteristics of emergency department (ED) frequent users differ from those of other ED patients.
  
  
  METHODS
  A cross-sectional and retrospective cohort study was performed using a database of all 348,858 visits to the San Francisco General Hospital ED during a five-year period (July 1, 1993, to June 30, 1998). A "frequent user" visited the ED five or more times in a 12-month period.
  
  
  RESULTS
  Frequent users constituted 3.9% of ED patients but accounted for 20.5% of ED visits. The relative risk (RR) of frequent use was high among patients who were homeless (RR = 4.5), African American (RR = 1.8), and Medi-Cal sponsored (RR = 2.1). Frequent users were more likely to be seen for alcohol withdrawal (RR = 4.4), alcohol dependence (RR = 3.4), and alcohol intoxication (RR = 2.4). Frequent users were also more likely to visit for exacerbations of chronic conditions, including sickle cell anemia (RR = 8.0), renal failure (RR = 3.6), and chronic obstructive pulmonary disease (RR = 3.3). They were less likely to visit for all forms of trauma (RR = 0.43). Survival analysis showed that only 38% of frequent users for one year remained frequent users the next year. However, 56% of frequent users for two consecutive years remained frequent users in the third year.
  
  
  CONCLUSIONS
  Frequent use of the ED reflects the urban social problems of homelessness, poverty, alcohol abuse, and chronic illness. Frequent use of the ED shows a high rate of decline from one year to the next. This rate of decline slows after the first year and suggests the existence of a smaller group of chronic frequent users.
authors.affiliation: University of California, San Francisco, School of Medicine, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Mandelberg
authors.forename: R E
authors.initials: RE
authors.lastname: Kuhn
authors.forename: M A
authors.initials: MA
authors.lastname: Kohn
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006773:Hospitals, Municipal / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D012495:San Francisco / Q000453:epidemiology; D017678:Sex Distribution; D012959:Socioeconomic Factors; D014505:Urban Population / Q000706:statistics & numerical data; D014600:Utilization Review / Q000706:statistics & numerical data*