Disability-Adjusted Life Years (DALYs) are calculated as the sum of which components?

• A. Years lived with disability
• B. Years of life lost due to premature mortality
• C. Disability-adjusted life years equal the sum of years of life lost and years lived with disability.
• D. Life expectancy and infant mortality

Answer: (C)

Disability-Adjusted Life Years reflect the total burden of disease by combining two aspects: premature death and time lived with disability. One part is years of life lost due to premature mortality, based on a standard life expectancy. The other part is years lived with disability, computed by multiplying the duration of disability by its severity (a disability weight). Adding these two pieces gives the total DALYs. So the best description is that DALYs equal the sum of years of life lost and years lived with disability. The other options only capture one piece or describe unrelated measures, so they don’t describe the full composite metric.