Interhospital variation in Medicare spending for infections after coronary artery bypass grafting and surgical aortic valve replacement.

Background: Infections following cardiac surgery are common and associated with increased complications and spending. While 1 in 5 beneficiaries experience a postoperative infection within 180 days, rates vary by 40% in absolute terms across hospitals. Efforts to reduce healthcare expenditures would benefit from associating interhospital variability in infection rates with Medicare spending. Methods: A total of 6439 coronary artery bypass grafting and/or surgical aortic valve replacement procedures between 2017 and 2022 across 33 hospitals in Michigan were evaluated using a clinical and administrative dataset. The primary outcome was overall and component inflation-adjusted spending within 180 days after surgery. Spending was compared across risk-adjusted terciles of hospital infection rates and phase of care. Results: The mean age (SD) of the cohort was 71.2 (7.7) years, with 29.1% female patients and 4.8% black patients. The mean adjusted infection rates across the low versus high terciles were 13.2% (2.3%) and 26.7% (6.5%) ( Conclusions: Spending following cardiac surgery varies across hospital risk-adjusted infection rate terciles. Infection prevention interventions could enhance cardiac surgical value.