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. Methods-We analyzed Interventional Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes as shown on Medicare bills to 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 beneficiaries) in 1985, the frequency of carotid endarterectomy among Medicare beneficiaries declined to 46571 (14.3 per 10000) in 1989 and then rose to 108275 (28.6 per 10000) in 1996. Patients were predominantly aged 65 to 74 years, male, and white; surgery occurred mainly in large, urban, 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 clinical trials. Perioperative mortality both improved and converged over time but did not attain the rates reported by the trials. Patients aged 85+ years suffered twice the average perioperative mortality.