title: A population-based analysis of the clinical course of 10,304 patients with acute cholecystitis, discharged without cholecystectomy.
abstract: BACKGROUND
  Randomized trials and expert opinion support early laparoscopic cholecystectomy for most patients with acute cholecystitis (AC); however, practice patterns remain variable worldwide, and delayed cholecystectomy remains a common practice. We therefore present a population-based analysis of the clinical course of patients with AC discharged without cholecystectomy.
  
  
  METHODS
  Using administrative databases capturing all emergency department (ED) visits and hospital admissions within a geographic region encompassing 13 million persons, we identified adults with a first emergency admission for uncomplicated AC during the period of 2004 to 2011. In those discharged without cholecystectomy, the probability of a subsequent gallstone-related event (gallstone-related ED visit or hospital admission) was evaluated using Kaplan-Meier methods. The association of patient characteristics with time to first gallstone-related event after discharge was explored through multivariable time to event analysis.
  
  
  RESULTS
  Of 25,397 patients with AC, 10,304 (41%) did not undergo cholecystectomy on first admission. The probability of a gallstone-related event by 6 weeks, 12 weeks, and 1 year after discharge was 14%, 19%, and 29% respectively. Of these events, 30% were for biliary tract obstruction or pancreatitis. When controlling for sex, income, and comorbidity level, the risk of a gallstone-related event was highest for patients 18 years to 34 years old.
  
  
  CONCLUSIONS
  For patients who do not undergo cholecystectomy on first admission for AC, the probability of a gallstone-related ED visit or hospital admission within 12 weeks of discharge is 19%. The increased risk in younger patients reinforces the value of early cholecystectomy in the nonelderly.
  
  
  METHODS
  Prognostic study, level III; therapeutic study, level IV.
authors.affiliation: Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada. charles.demestral@mail.utoronto.ca
authors.forename: Charles
authors.initials: C
authors.lastname: de Mestral
authors.forename: Ori D
authors.initials: OD
authors.lastname: Rotstein
authors.forename: Andreas
authors.initials: A
authors.lastname: Laupacis
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Hoch
authors.forename: Brandon
authors.initials: B
authors.lastname: Zagorski
authors.forename: Avery B
authors.initials: AB
authors.lastname: Nathens
mesh_terms: D000368:Aged; D002763:Cholecystectomy; D041881:Cholecystitis, Acute / Q000150:complications / Q000628:therapy*; D005260:Female; D042882:Gallstones / Q000209:etiology; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D011379:Prognosis; D012008:Recurrence; D013997:Time Factors