The Hospital Compare mortality model and the volume-outcome relationship.

Objective: We ask whether Medicare's Hospital Compare random effects model correctly assesses acute myocardial infarction (AMI) hospital mortality rates when there is a volume-outcome relationship.

Data Sources/study Setting: Medicare claims on 208,157 AMI patients admitted in 3,629 acute care hospitals throughout the United States.

Study Design: We compared average-adjusted mortality using logistic regression with average adjusted mortality based on the Hospital Compare random effects model.