Figure 2.

How Much Does the Hospital Compare Model Emphasize an Individual Hospital's Observed Mortality Rate When Calculating the Predicted Mortality That Is Provided to the Public?

Notes. The figure provides the value of λ where P/E=λ (O/E)+(1−λ)(E/E). Because Hospital Compare does not include volume or any hospital characteristics in the model, the (1−λ) term is multiplied by 1, which represents the national average or typical hospital death rate. As hospital acute myocardial infarction (AMI) volume increases, λ increases, suggesting an increasing emphasis on the hospitals own O/E. As hospital AMI volume decreases, λ decreases, and the Hospital Compare model emphasizes the national mortality rate (E/E) rather than the hospitals own observed mortality rate (O/E) when making the prediction P/E.