The ratio or efficiency of effects (benefits or outcomes) gained relative to the costs invested; used to evaluate investment efficiency.
新しい広告キャンペーンの費用対効果を測定してから予算を決めよう。
Let's measure the cost-effectiveness of the new advertising campaign before deciding the budget.
費用対効果が高い施策に優先的に投資する必要がある。
We need to prioritize investments in measures that have high cost-effectiveness.
この治療法は効果があるが費用対効果が低いと判断された。
This treatment is effective, but it was judged to have low cost-effectiveness.