Which metric is used to reflect the severity-adjusted resource intensity of the patient mix over a given period?

• A. CMI
• B. ROM
• C. DRG
• D. MCC

Answer: (A)

Case Mix Index quantifies how resource-intensive the patient mix is, after adjusting for illness severity over a period. It’s calculated by dividing the sum of DRG weights for all discharges in the period by the number of discharges, with each DRG weight reflecting the typical resource use for that diagnosis group. Because it averages the expected resource use across the entire patient population, a higher CMI means a sicker, more resource-demanding mix, while a lower CMI indicates less intensive care needs. The other terms aren’t designed to measure this period-wide intensity: DRG is the grouping system itself, MCC is a specific type of severity/comorbidity within DRGs, and ROM is a severity metric focused on mortality risk rather than overall resource use of the patient mix.