In burden of disease measures, what do YLL and YLD stand for?

• A. Years of Life Lost and Years Lived with Disability
• B. Youth Life Years and Years Lived with Death
• C. Years Lifed Lost and Life Years Displaced
• D. Years Lost in Life and Years Lived in Disability

Answer: (A)

In burden of disease measures, the key ideas are to quantify both fatal and non-fatal health loss. YLL stands for Years of Life Lost and captures premature mortality by comparing the age at death with a standard life expectancy—each death contributes the number of years a person would have lived had they reached that standard. YLD stands for Years Lived with Disability and measures non-fatal health loss by multiplying the duration of a condition by a disability weight that reflects its severity, giving the equivalent number of years lived with disability. When you add these together, you get a sense of overall burden (DALYs). The other options use terms that aren’t part of this framework, so they don’t describe the established concepts.