A decision theory approach to measuring severity in illness.

The purpose of this study was to evaluate the applicability of a multiattribute utility model for measuring the severity of a patient's illness. A single medical problem (an analysis of the costs and benefits of different burn care systems) was used to test the model. Physicians estimated the relative importance of and severity functions for criteria influencing severity. The model's estimates of severity were compared with survival rates of more than 6000 actual patients and with physicians' rankings of hypothetical patients. Although continued validation is needed, the multiattribute utility model appears to have potential as an index for illness severity and, possibly, health status.