What does Case Mix Index (CMI) measure?

What does Case Mix Index (CMI) measure?

• A. The average relative weight of all cases treated at a facility or by a physician, which reflects resource intensity or clinical severity of a specific group in relation to the other groups in the classification system
• B. The total number of admissions in a period
• C. The average length of stay per patient
• D. The percentage of readmissions

Answer: (D)

CMI measures the average resource intensity of a facility’s patient mix, based on DRG weights. Each case is assigned a DRG weight that reflects the expected use of resources (costs, complexity, care needs). By averaging these weights across all cases, CMI shows whether the typical patient treated is more or less resource-intensive. A higher CMI means more complex or resource-demanding cases; a lower CMI means less complex ones. This is different from total admissions (volume), average length of stay (LOS per patient), or readmission rate (quality/throughput).

CMI measures the average resource intensity of a facility’s patient mix, based on DRG weights. Each case is assigned a DRG weight that reflects the expected use of resources (costs, complexity, care needs). By averaging these weights across all cases, CMI shows whether the typical patient treated is more or less resource-intensive. A higher CMI means more complex or resource-demanding cases; a lower CMI means less complex ones. This is different from total admissions (volume), average length of stay (LOS per patient), or readmission rate (quality/throughput).