Substantial variation exists in post-cardiac arrest outcomes across Michigan hospitals

Aim: Resuscitation from out of hospital cardiac arrest (OHCA) requires success across the entire chain of survival. Using a large state-wide registry, we characterized variation in clinical outcomes at hospital discharge in Michigan hospitals. Methods: We utilized the Michigan Cardiac Arrest Registry to Enhance Survival (CARES) and included adult OHCA subjects with return of spontaneous circulation (ROSC) from 2014 - 2017 that survived to hospital admission. 39 Michigan hospitals were included which managed >30 cases during the study period. Multilevel logistic regression, controlling for both subject characteristics and clustering of subjects within hospitals, assessed variation across hospitals in survival to hospital discharge and survival with cerebral performance category (CPC 1-2). Results: There were 5,486 CARES subjects that survived to hospital admission, and 4,690 met inclusion for analysis. Of 39 included hospitals, median survival to discharge was 31.3% (range 12.5%-46.7%) and median survival to discharge with CPC 1-2 was 25.0% (range 5.2%-42.2%). We identified 12-fold variation in the utilization of TTM by hospital (median 47.9%, range 6.7%-80.0%) for all admitted subjects. Similarly, there was nearly an eightfold variation in LHC for all post-arrest subjects (median 22.1%, range 5.4%-42.2%). In multivariable analyses, median adjusted survival to discharge was 26.9% (range 18.1%-42.1%) and median adjusted survival to discharge with CPC 1-2 was 21.3% (range 9.6%-32.1%). Conclusion: We observed substantial variation in clinical outcomes at discharge between Michigan hospitals, including a four-fold range of survival and eight-fold range of survival with CPC 1-2. This variation was ameliorated but still persisted in adjusted modeling. Variation in post arrest survival by hospital was not fully explained by available covariates, which suggests the possibility of improving post-arrest clinical outcomes at some hospitals via quality improvement activities.