title: Cholangiography during laparoscopic cholecystectomy--cumulative sum analysis of an institutional learning curve.
abstract: The ability to perform intraoperative cholangiography during laparoscopic cholecystectomy is an essential skill for the laparoscopic biliary surgeon. The volume of experience required to be able to consistently obtain a cholangiogram during laparoscopic cholecystectomy has not been determined. Cumulative sum analysis is a statistical technique which generates a graphical display that identifies periods of performance that fall below a predetermined standard for a given task. The cumulative sum (S(n)) for a series of observations is defined as: S(n)= summation operatorX(I) - X(o), where X(I) = 0 for a success, X(I) = 1 for a failure, and X(o) is the acceptable failure rate for the process under study. This function is plotted against the number of observations to create a curve. When the curve has a positive slope, the acceptable failure rate is being exceeded. When it reaches a plateau, the observed failure rate is equal to the acceptable failure rate. When the curve has a negative slope, the observed failure rate is lower than the acceptable failure rate. We performed a cumulative sum analysis of the first 97 intraoperative cholangiograms attempted during lap-aroscopic cholecystectomy at our institution. The results demonstrated that 46 cases were required to reach a level of proficiency where a cholangiogram could be obtained in 95% of attempts. Success rates of 85% and 90% were achieved at 16 and 25 cases, respectively. This form of analysis is a useful tool for estimating the number of attempts required to achieve a desired success rate when learning new procedures.
authors.affiliation: Surgical Service, Veterans Affairs Medical Center, and the Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
authors.forename: M
authors.initials: M
authors.lastname: Molloy
authors.forename: R H
authors.initials: RH
authors.lastname: Bower
authors.forename: P O
authors.initials: PO
authors.lastname: Hasselgren
authors.forename: B J
authors.initials: BJ
authors.lastname: Dalton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002758:Cholangiography / Q000706:statistics & numerical data*; D017081:Cholecystectomy, Laparoscopic / Q000706:statistics & numerical data; D002983:Clinical Competence / Q000706:statistics & numerical data*; D005260:Female; D005762:Gastroenterology / Q000193:education*; D006801:Humans; D007430:Intraoperative Care / Q000706:statistics & numerical data*; D007858:Learning; D008297:Male; D008875:Middle Aged; D012042:Registries