Association between preoperative cardiac risk assessment and health care costs in major noncardiac surgery: a multicentre health economic analysis.

Purpose: Patients with impaired functional capacity who undergo major surgery are at increased risk of postoperative morbidity including complications and increased length of stay. These outcomes have been associated with increased hospital and health system costs. We aimed to assess whether common preoperative risk indices are associated with postoperative cost.
Methods: We conducted a health economic analysis focused on the subset of Measurement of Exercise Tolerance before Surgery (METS) study participants in Ontario, Canada. Participants were scheduled for major elective noncardiac surgery and underwent several preoperative assessments of cardiac risk, including physicians' subjective assessment, Duke Activity Status Index (DASI) questionnaire, peak oxygen consumption, and N-terminal pro-B-type natriuretic peptide concentration. Using linked health administrative data, postoperative costs were calculated for both one year and in-hospital. Using multiple regression models, we tested for association between the preoperative measures of cardiac risk and postoperative costs.
Results: Our study included 487 patients (mean [standard deviation] age 68 [11] yr and 47.0% female) who underwent noncardiac surgery between 13 June 2013 and 8 March 2016. Overall, the median [interquartile range] cost incurred within one year postoperatively was CAD 27,587 [13,902-32,590], of which CAD 12,928 [10,253-12,810] were incurred in-hospital and CAD 14,497 [10,917-15,017] were incurred by 30 days. None of the four preoperative measures of cardiac risk assessment were associated with costs incurred in hospital or at one year postoperatively. This lack of strong association persisted in sensitivity analyses considering type of surgical procedure, burden of preoperative cost, and when costs were categorized as quantiles.
Conclusion: In patients undergoing major noncardiac surgery, common measures of functional capacity are not consistently associated with total postoperative cost. Until further data exist that differ from this analysis, clinicians and health care funders should not assume that preoperative measures of cardiac risk are associated with annual health care or hospital costs for such surgeries.
(© 2023. Canadian Anesthesiologists' Society.)