Physicians in health care management: 3. Case Mix Groups and Resource Intensity Weights: an overview for physicians.

In the first of two articles on the subject, the authors explain what Case Mix Groups (CMGs) and Resource Intensity Weights (RIWs) are and how they are used. The former categorize hospital patients into groups. The latter are ratios showing the relative use of hospital resources for a typical case (successful course of treatment in an acute care hospital and discharge when the patient no longer requires the hospital's services) and atypical cases (death, transfer, sign-out and substantially longer than average stay) in each CMG. As such, CMGs and RIWs define the relation between the medical and financial dimensions of hospital cases for use in planning and management. Ontario and Alberta are the first provinces to use them to adjust hospital funding. CMGs are limited by the number of diagnoses contained in each category, and RIWs are limited by the use of New York cost data due to the lack of Canadian data.