Direct costs of coronary artery bypass grafting in patients aged 65 years or more and those under age 65

Abstract

Background: Over the past 20 years, there have been marked increases in rates of coronary artery bypass grafting (CABG) among older people in Canada. The objectives of this study were to accurately estimate the direct medical costs of CABG in older patients (age 65 years or more) and to compare CABG costs for this age group with those for patients less than 65 years of age.

Methods: Direct medical costs were estimated from a sample of 205 older and 202 younger patients with triple-vessel or left main coronary artery disease who underwent isolated CABG at The Toronto Hospital, a tertiary care university-affiliated hospital, between Apr. 1, 1991, and Mar. 31, 1992. Costs are expressed in 1992 Canadian dollars from a third-party payer perspective.

Results: The mean costs of CABG in older and younger patients respectively were $16,500 and $15,600 for elective, uncomplicated cases, $23,200 and $19,200 for nonelective, uncomplicated cases, $29,200 and $20,300 for elective, complicated cases, and $33,600 and $23,700 for nonelective, complicated cases. Age remained a significant determinant of costs after adjustment for severity of heart disease and for comorbidity. Between 59% and 91% of the cost difference between older and younger patients was accounted for by higher intensive care unit and ward costs.

Interpretation: CABG was more costly in older people, especially in complicated cases, even after an attempt to adjust for severity of disease and comorbidity. Future studies should attempt to identify modifiable factors that contribute to longer intensive care and ward stays for older patients.