TABLE 1.

Types of economic evaluation

Type of evaluation	Unit for benefit/effects	Formula	Summary measure
Cost-effectiveness analysis (CEA)	Natural units		Cost-effectiveness ratio
Interpretation: The cost-effectiveness ratio is $100:1 ($5000/50 cases), meaning the program costs $100 for each disease case avoided.
Benefit–cost analysis (BCA)	Dollars		Benefit–cost ratio (BCR)
Interpretation: The BCR is 2.5:1 ($12,500/$5000), meaning the program generates $2.50 in savings for every $1 spent.
Return on investment (ROI)	Dollars		Percent return
Interpretation: The ROI is 150% ($7500/$5000), meaning the program generates $1.50 in net savings (i.e., profit) for every $1 spent.