VALIDITY OF CRITERIA USED FOR DETECTING UNDERUSE OF CORONARY REVASCULARIZATION

Objective.-To assess criteria used for detecting underuse of coronary artery revascularization procedures in terms of patient outcomes. Desi gn.-Retrospective cohort study using medical records supplemented by a telephone survey and review of county death records. Setting.-Four pu blic hospitals and two academically affiliated private hospitals in Lo s Angeles County, California. Participants.-A total of 671 patients wh o had coronary angiography between June 1, 1990, and September 30, 199 1, and who met explicit clinical criteria for the necessity of coronar y artery bypass graft (CABG) surgery or percutaneous transluminal coro nary angioplasty (PTCA). Main Outcome Measures.-For all patients (n=67 1), we estimated the association between receipt of necessary revascul arization and mortality (median follow-up after angiography, 797 days) after adjusting for potential confounders. For the patients completin g the telephone interview (n=374), we examined the relationship betwee n receipt of necessary revascularization and frequency of chest pain. Results.-Patients who received necessary revascularization within 1 ye ar of angiography had tower mortality than those who did not (8.7% vs 15.8%, P=.01), and this association persisted after adjustment for ext ent of coronary artery disease, clinical symptom complex, ejection fra ction, and cardiac surgical risk index (adjusted odds ratio=0.49; 95% confidence interval, 0.28 to 0.86). The same general results were obta ined whether revascularization was received within 1 year or within 30 days of the catheterization, whether panelists' ratings or individual clinical variables were entered as covariates, and whether the statis tical procedure used was logistic regression or Cox proportional hazar ds analysis. In addition, among patients responding to the telephone s urvey, those receiving necessary revascularization had less chest pain at follow-up (P=.03). Conclusions.-Among patients meeting criteria fo r the necessity of revascularization, those receiving a revascularizat ion procedure within I year had lower mortality than those treated med ically. These results support the validity of the RAND/UCLA criteria f or detecting underuse of these procedures, but more research is needed to confirm the findings and to determine the validity of guidelines f or other procedures.