The appropriateness of coronary artery bypass graft surgery in academic medical centers. Working Group of the Appropriateness Project of the Academic Medical Center Consortium

Abstract

Objective: To compare the appropriateness of use of coronary artery bypass graft (CABG) surgery in Academic Medical Center Consortium hospitals as judged 1) according to criteria developed by an expert panel, 2) according to revisions of those criteria made by cardiac surgeons from the Academic Medical Center Consortium, and 3) by review of cases by the surgeons responsible for those cases.

Design: Retrospective, randomized medical record review.

Setting: 12 Academic Medical Center Consortium hospitals.

Patients: Random sample of 1156 patients who had had isolated CABG surgery in 1990.

Main outcome measures: 1) Percentage of patients with indications for which CABG surgery was classified as appropriate, Inappropriate, or of uncertain appropriateness and 2) percentage of cases in which CABG surgery was judged inappropriate or uncertain for which ratings changed after local case review.

Results: Data were retrieved from medical records by trained abstractors using an explicit data collection instrument. Cases in which CABG surgery was judged to be inappropriate or uncertain were individually reviewed by the responsible surgeons. According to the expert panel ratings, 83% of the CABG operations (95% CI, 81% to 85%) were necessary, 9% (CI, 8% to 10%) were appropriate, 7% (CI, 5% to 8%) were uncertain, and 1.6% (CI, 0.6% to 2.5%) were inappropriate. These rates are almost identical to those found in a previous study that was done in New York State and that used the same criteria (in that study, 91% of operations were classified as necessary or appropriate, 7% were classified as uncertain, and 2.4% were classified as inappropriate). Rates of inappropriate procedures varied from 0% to 5% among the 12 member hospitals (P = 0.02). The Academic Medical Center Consortium cardiac surgeons revised 568 (24%) of the indications used by the expert panel. However, because those revisions altered the appropriateness ratings in both directions and affected only 50 cases (4%), the net effect of the revisions was slight: The rate of inappropriate CABG surgery increased from 1.6% to 1.9%. Local review found that data collection errors had caused erroneous ratings in 12.5% of 64 cases in which surgery had been classified as inappropriate or uncertain.

Conclusions: The Academic Medical Center Consortium hospitals had low rates of inappropriate and uncertain use of CABG surgery, regardless of the criteria used for assessment. Even though surgeons from the Consortium revised the appropriateness ratings extensively, their revisions had a negligible effect on the overall assessment of appropriateness. However, because of potential data collection errors, appropriateness criteria should be used for individual case audits only if supplemented by subsequent physician review.