A Report Card for Report Cards

Almost daily, we hear about the effects—present and predicted—of managed care on health in the United States. The ability of those who purchase or “manage” care to compare the performances of individual physicians and hospitals is dependent on systems that can effectively compare outcomes for different types of patients across physicians and hospitals. In this issue, Iezzoni and colleagues [1] show that four of the computer-based systems marketed to meet this need give different answers about severity of illness for the same patients.

The problems highlighted by Iezzoni and colleagues might well be worse than the study indicates. First, these authors studied patients with acute myocardial infarction, an acute illness that has short-term mortality and requires hospitalization. For diseases with mortality rates far lower than the 13% seen in this study, statistical models generally perform less well and demand more data. Almost all patients with acute myocardial infarction are admitted to nearby hospitals, where their outcomes can be readily audited using conventional hospital data systems. In contrast, in patients having procedures such as coronary artery bypass surgery, the underlying disease is treated alternatively without surgery in the outpatient setting. The prudent investigator must consider selection bias, that is, the effects of the decision to choose surgery on the outcome of patients who elect to have surgery [2, 3]. If the outcome is changed from inpatient mortality to 1-year survival or nonfatal adverse events or length …