YLL and YLD are components used to calculate what overall measure?

• A. Quality of life index.
• B. DALYs, combining Years of Life Lost and Years Lived with Disability.
• C. Life expectancy adjusted by income.
• D. Disability index for policy budgeting.

Answer: (B)

YLL and YLD are used to quantify the total burden of disease in a population by producing a single measure: DALYs, disability-adjusted life years. YLL captures the impact of premature death by comparing each death to a standard life expectancy and summing the years lost. YLD captures non-fatal health loss by weighing the number of people living with a disability by its severity and duration. Adding these together gives DALYs, which reflect both years of life lost due to early death and years lived with disability, providing a comprehensive view of overall health burden. This is why DALYs is the best answer. Other concepts like quality of life indexes, life expectancy adjusted by income, or disability indices for budgeting refer to different ideas and don’t combine mortality and morbidity into a single burden metric.