The burden imposed by a disease can be measured in many ways, including the number of deaths attributed to it, the total number of cases, the number of new cases that occur in a given year, hospitalization rates, potential years of life lost, and other measures that combine mortality and quality-of-life information. Another approach to assessing the burden of disease is to estimate the associated “cost of illness” (or COI), which expresses the multidimensional impact of a health problem in dollars. A COI study of a particular health problem usually includes estimates of the costs of health care services, losses in productivity from illness and premature death, and other expenditures and resource losses that can be attributed to the health condition. Estimates for different diseases often are not directly comparable to one another because of variations in methods, data sources, and underlying assumptions (National Institutes of Health 1997).
