Profiles of physician practice and patient severity of illness.

We report on a study that examined physician practice profiles using two methods of patient classification: the Severity of Illness Index and diagnosis-related groups (DRGs). When used together with conventional management information and DRGs, the Severity of Illness Index permitted useful comparisons to be made among physicians; differences in both case-mix and severity could be estimated. In 37 per cent of the physicians studied, we found differences of more than $10,000 in the apparent impact of a physician on the hospital's financial position, depending on whether one controlled for severity or not. The extent to which these differences in impact could be due to quality of care differences is an area for future research. However, the findings that 37 per cent of the physicians in the study may be wrongly identified as over- or under-utilizers suggest long-term public health consequences of preparing physician profiles based on unadjusted DRGs.