Objectives: To determine whether cholecystectomy rates among the elderly increased following the introduction of laparoscopic cholecystectomy in 1989, and to assess whether changes in rates were accompanied by lower clinical thresholds for performing cholecystectomy.
Design: Time-series quasi-experimental design based on quarterly observations from 1986 to 1993. Data were obtained from Medicare hospital discharge files for Pennsylvania.
Patients: Medicare patients aged 65 years or older who resided in Pennsylvania, did not have end-stage renal disease, and underwent cholecystectomy in Pennsylvania from 1986 to 1993.
Main outcome measures: Cholecystectomy rates per 1000 elderly Medicare beneficiaries, stage of gallstone disease (uncomplicated vs complicated) at cholecystectomy, type of admission (elective vs urgent/emergent), patient age and comorbidities, and 30-day postoperative mortality.
Results: Cholecystectomy rates increased 22% from 1989 to 1993. The proportions of cholecystectomy patients with uncomplicated gallstone disease and with elective admissions declined from 1986 to 1989 but then increased rapidly after laparoscopic cholecystectomy was introduced. In contrast, the age distribution and comorbidities of cholecystectomy patients did not change during the study period. Postoperative mortality rates were stable from 1986 to 1989 but decreased thereafter.
Conclusions: Growth in cholecystectomy rates following the introduction of laparoscopic cholecystectomy was accompanied by evidence of lower clinical thresholds for performing surgery. The normative, or prescriptive, implications of lower cholecystectomy thresholds require further analyses that consider lower direct medical costs and indirect costs and reduced postoperative morbidity after laparoscopic cholecystectomy.