Comparing apples with apples in clinical populations: applications of the adjusted Clinical Group System in British Columbia.

This article reviews the Adjusted Clinical Group Case-Mix System and describes how it is being applied in the management of physician services in British Columbia. Developed in the United States for management and research, adjusted clinical groups are used to measure the illness burden and health service needs of individuals and, when aggregated, of populations, by grouping the range of conditions coded on physician claims and hospital care records over a defined time period, typically one year. In Canadian and United States settings, adjusted clinical groups are up to five times more predictive of ambulatory resource use than are age and sex groups alone. The article describes how adjusted clinical groups are being applied to adjust capitation payments for physician groups in British Columbia's Primary Care Demonstration Project and profiles of physician practice activity.