An economic evaluation compares PT to injections using additional cost per health gain. What statistic is most likely being interpreted?

• A. NNT
• B. ICER
• C. ROI
• D. DALY

Answer: (B)

The main idea here is the Incremental Cost-Effectiveness Ratio. When you compare two health interventions, this statistic shows how much extra money you must spend to gain an additional unit of health benefit with one option over the other. It’s calculated by taking the difference in costs between PT and injections and dividing by the difference in their health outcomes (for example, QALYs or life-years gained).

Interpreting ICER helps you judge value: a lower ICER or one below a willingness-to-pay threshold means the extra health benefit is worth the extra cost; a high ICER suggests the extra health gain isn’t worth the extra money. If PT is both cheaper and more effective, it dominates injections, which is an especially favorable outcome.

NNT is a clinical efficiency measure (how many patients need treatment for one additional benefit) and doesn’t involve costs. ROI focuses on financial return rather than health outcomes. DALY is a health burden measure, not the cost per health gain ratio.