title: Determinants of the relationship between cost and survival time after elective adult cardiac surgery.
abstract: Cardiac surgery is increasingly performed on elderly patients with multiple comorbid conditions, but the determinants of the relationship between cost and survival time after cardiac surgery for patients with a serious cardiac condition remain uncertain. Using the long-term outcome data of a cohort study on adult cardiac surgical patients, the relationship between cost and survival time after cardiac surgery from a hospital service perspective was determined. The total cost for each patient was estimated by the costs of the surgical procedures, intra-aortic balloon pump utilisation, operating theatre utilisation, blood products, intensive care unit stay and cumulative hospital stay up to a median follow-up time of 30 months. Of the 2131 patients considered in this study, a total cost >A$100,000 per life-year after cardiac surgery was observed only in 171 patients (8.0%, 95% confidence interval 6.9 to 9.3%). Age, Charlson Comorbidity Index and EuroSCORE were all related to the cost per life-year after cardiac surgery, but EuroSCORE (odds ratio 1.26 per score increment, 95% confidence interval 1.18 to 1.35, P=0.001) was, by far, the most important determinant and explained 32% of the variability in cost per life-year after cardiac surgery. Patients with a high EuroSCORE were associated with a substantially longer length of intensive care unit stay and cumulative hospital stay, as well as a shorter survival time after cardiac surgery compared to patients with a lower EuroSCORE. Of all the subgroups of patients examined, only patients with a EuroSCORE >5 were consistently associated with a cost >A$100,000 per life-year (cost per life-year $183,148, 95% confidence interval 125, 394 to 240, 902).
authors.affiliation: Department of Intensive Care, Royal Perth Hospital and School of Population Health, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: K M
authors.initials: KM
authors.lastname: Ho
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures / Q000191:economics* / Q000401:mortality*; D005260:Female; D017048:Health Care Costs; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged
keywords: comorbidity; costs; health economics; outcomes; survival time