title: Biosurveillance of ED visits for gastroenteritis.
abstract: OBJECTIVE
  Our objective was to characterize emergency department (ED) visits for gastroenteritis by season and age and develop a predictive model.
  
  
  METHODS
  We performed a retrospective cohort study of patients seen in 19 EDs from 1988 to 2002. We examined differences in the annual peaks of younger (<60 months) and older (>60 months) age groups and developed a time series regression model.
  
  
  RESULTS
  Of the 5,182,019 total visits, 88,504 were for gastroenteritis. On average, the percentage of gastroenteritis on the peak days was higher in the younger (26%) than older group (4%), and the peaks for the younger group occurred 36 days after those for the older group.
  
  
  CONCLUSIONS
  Emergency department visits for gastroenteritis vary greatly by season and age. Our time series predictive model was a good fit to actual incidence patterns. These variations should be accounted for in designing a system to detect bioterrorism and for surveillance of naturally occurring epidemics.
authors.affiliation: UMDNJ Robert Wood Johnson Medical School/School of Public Health, Piscataway, NJ 08854, USA.
authors.forename: Vashun A
authors.initials: VA
authors.lastname: Rodriguez
authors.forename: Michael E
authors.initials: ME
authors.lastname: Silverman
authors.forename: Dennis G
authors.initials: DG
authors.lastname: Cochrane
authors.forename: Barnet
authors.initials: B
authors.lastname: Eskin
authors.forename: Pamela
authors.initials: P
authors.lastname: Ohman-Strickland
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rothman
authors.forename: John R
authors.initials: JR
authors.lastname: Allegra
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D023482:Bioterrorism; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009515:New Jersey / Q000453:epidemiology; D011159:Population Surveillance; D012044:Regression Analysis; D012189:Retrospective Studies; D012621:Seasons