title: Rate of elective cholecystectomy and the incidence of severe gallstone disease.
abstract: BACKGROUND
  The use of elective cholecystectomy has increased dramatically following the widespread adoption of laparoscopic cholecystectomy. We sought to determine whether this increase has resulted in a reduction in the incidence of severe complications of gallstone disease.
  
  
  METHODS
  We examined longitudinal trends in the population-based rates of severe gallstone disease from 1988 to 2000, using a quasi-experimental longitudinal design to assess the effects of the large increase in elective cholecystectomy rates after 1991 among people aged 18 years and older residing in Ontario. We also measured the rate of hospital admission because of acute diverticulitis, to control for secular trends in the use of hospital care for acute abdominal diseases.
  
  
  RESULTS
  The adjusted annual rate of elective cholecystectomy per 100,000 population increased from 201.3 (95% confidence interval [CI] 197.0-205.8) in 1988-1990 to 260.8 (95% CI 257.1- 264.5) in 1992-2000 (rate ratio [RR] 1.35, 95% CI 1.32- 1.38, p 0.001). An anomalously high number of elective cholecystectomies were performed in 1991. Overall, the annual rate of severe gallstone diseases (acute cholecystitis, acute biliary pancreatitis and acute cholangitis) declined by 10% (RR 0.90, 95% CI 0.88- 0.91) for 1992-2000 as compared with 1988-1991. This decline was entirely due to an 18% reduction in the rate of acute cholecystitis (RR 0.82, 95% CI 0.80-0.84).
  
  
  CONCLUSIONS
  The increase in the rate of elective cholecystectomy that occurred following the introduction of laparoscopic cholecystectomy in 1991 was associated with an overall reduction in the incidence of severe gallstone disease that was entirely attributable to a reduction in the incidence of acute cholecystitis.
authors.affiliation: The Institute for Clinical Evaluative Sciences, University of Toronto, Toronto, Ont. david.urbach@uhn.on.ca
authors.forename: David R
authors.initials: DR
authors.lastname: Urbach
authors.forename: Thérèse A
authors.initials: TA
authors.lastname: Stukel
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D002761:Cholangitis / Q000453:epidemiology* / Q000209:etiology; D002763:Cholecystectomy / Q000639:trends*; D017081:Cholecystectomy, Laparoscopic / Q000639:trends; D002764:Cholecystitis / Q000453:epidemiology* / Q000209:etiology; D002769:Cholelithiasis / Q000150:complications / Q000453:epidemiology / Q000601:surgery*; D004238:Diverticulitis / Q000453:epidemiology; D017558:Elective Surgical Procedures / Q000639:trends; D005260:Female; D042882:Gallstones / Q000150:complications / Q000601:surgery; D006760:Hospitalization / Q000639:trends; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D010195:Pancreatitis / Q000453:epidemiology* / Q000209:etiology