EPIDEMIOLOGY OF CAROTID ENDARTERECTOMY AMONG MEDICARE BENEFICIARIES -1985-1996 UPDATE

Background and Purpose-This article describes changes in the rate and outcome of carotid endarterectomies among Medicare beneficiaries. Meth ods-We analyzed Interventional Classification of Diseases, 9th Revisio n, Clinical Modification (ICD-9-CM) codes as shown on Medicare bills t o calculate carotid endarterectomy frequency, rate, and perioperative mortality by patient demography and hospital characteristics. Results- After initially peaking at 61273 procedures (20.6 per 10000 beneficiar ies) in 1985, the frequency of carotid endarterectomy among Medicare b eneficiaries declined to 46571 (14.3 per 10000) in 1989 and then rose to 108275 (28.6 per 10000) in 1996. Patients were predominantly aged 6 5 to 74 years, male, and white; surgery occurred mainly in large, urba n, nonprofit, and teaching hospitals. Perioperative mortality declined from 3.0% in 1985 to 1.6% in 1996. Conclusions-The frequency and rate of carotid endarterectomy showed prompt response to reports from clin ical trials. Perioperative mortality both improved and converged over time but did not attain the rates reported by the trials. Patients age d 85+ years suffered twice the average perioperative mortality.