Distinguishing cost-effectiveness analysis (CEA) from cost-utility analysis (CUA).

• A. CEA uses monetary outcomes; CUA uses clinical outcomes only.
• B. CEA and CUA are identical.
• C. CEA uses natural health outcomes (e.g., life-years gained); CUA uses utility-weighted outcomes (e.g., QALYs).
• D. CEA requires WTP threshold; CUA does not.

Answer: (C)

Distinguishing feature: the type of effectiveness outcome used. In cost-effectiveness analysis, outcomes are natural health units such as life-years gained or cases prevented. These are concrete, fight-the-disease kind of measures that stay in the same natural unit across comparisons. In cost-utility analysis, outcomes are utility-weighted measures that combine length and quality of life, most commonly quality-adjusted life years (QALYs). QALYs incorporate how desirable, or preferable, different health states are, so they let you compare very different health interventions on a common scale that reflects patient preferences.

Because of this difference in what is measured, the statements that CEA uses monetary outcomes or that CUA uses clinical outcomes only aren’t the defining distinction. Similarly, both analyses can use thresholds to judge value, so saying one requires a willingness-to-pay threshold and the other does not isn’t accurate. The key point is that CEA sticks to natural health outcomes, while CUA translates those outcomes into utility-weighted measures like QALYs.