Which metric combines years of life lost due to premature death and years lived with disability?

• A. Disability-adjusted life years
• B. Life expectancy
• C. Years of potential life lost
• D. Crude death rate

Answer: (A)

This item tests understanding of burden of disease metrics that quantify total health loss in a population. The measure that combines years of life lost due to premature death with years lived with disability is the Disability-adjusted life year, or DALY.

DALYs reflect total health loss by adding two components. First, years of life lost (YLL) represent premature mortality: each death at an age contributes the number of years the person would have been expected to live, based on a standard life expectancy. This gives greater weight to deaths occurring at younger ages. Second, years lived with disability (YLD) capture non-fatal health outcomes by multiplying the number of people living with a given condition by a disability weight that reflects the severity of the condition and by the duration of that condition. By summing YLL and YLD, DALYs provide a single metric of overall disease burden, encompassing both death and disability.

This differs from life expectancy, which is the average number of years a person is expected to live and does not account for disease or disability. It also differs from years of potential life lost, which measures only premature mortality without considering non-fatal health states. Crude death rate counts deaths in a population without incorporating morbidity or age structure.