Sources of Hospital Variation in Postacute Care Spending After Cardiac Surgery

Postacute care is a major driver of cardiac surgical episode spending, but the sources of variation in spending have not been explored. The objective of this study was to identify sources of variation in postacute care spending within 90-days of discharge following coronary artery bypass grafting (CABG) and aortic valve replacement (AVR) and the relationship between postacute care spending and other postdischarge utilization.

A retrospective analysis was conducted of public and private administrative claims for Michigan residents insured by Medicare fee-for-service and Blue Cross Blue Shield of Michigan/Blue Care Network commercial and Medicare Advantage plans undergoing CABG (n=11 208) or AVR (n=6122) in 33 nonfederal acute care Michigan hospitals between January 1, 2015 and December 31, 2018. Postacute care use was present in 9662 (86.2%) CABG episodes and 4242 (69.3%) AVR episodes, with respective mean (SD) 90-day spending of $4398±$6124 and $3465±$5759. Across hospitals, mean postacute care spending ranged from $3280 to $8186 for CABG and $2246 to $7710 for AVR. Inpatient rehabilitation and skilled nursing facility care accounted for over 80% of the variation spending between low and high postacute care spending hospitals. At the hospital-level, postacute care spending was modestly correlated across procedures and payers. Spending associated with readmissions, emergency department visits, and outpatient facility care was significantly different between low and high postacute care spending hospitals in CABG and AVR episodes.

There was wide hospital variation in postacute care spending after cardiac surgery, which was primarily driven by differential use and intensity in facility-based postacute care. Optimizing facility-based postacute care after cardiac surgery offers unique opportunities to reduce potentially unwarranted care variation.