Health economists have developed a variety of ways of measuring the potential benefits of
improving health, including the cost-of-illness (COI) approach, WTP (preventive expenditures)
approach, cost–benefit analysis, cost–utility analysis (cost-effectiveness) analysis,
disability-adjusted life years (DALYs), quality-adjusted life years (QALYs), and healthy
years of life gained (HYLG) (disability-free life expectancy).