1 Health Metrics
1.1 YLLs, YLDs and DALYs
In this section are shown the methods used for building three key metrics: YLLs, YLDs and DALYs. These will be used throughout the book for making comparisons among the state of health of different countries.
The health metrics, and their components are used to measure the burden of disease and quantify the impact of diseases and injuries on individuals and populations. These metrics can help prioritize public health interventions and evaluate the effectiveness of public health programs.
1.2 YLL (Years of Life Lost)
YLL (Years of Life Lost) measures the number of years a person would have lived if they had not died prematurely due to a disease or injury. YLL is calculated by subtracting the age at death from the expected age at death in a population without the disease or injury.
1.3 YLD (Years Lived with Disability)
YLD (Years Lived with Disability) measures the number of years a person lives with a disability due to a disease or injury. It is calculated by multiplying the prevalence of a condition by the disability weight, which reflects the severity of the disability.
1.4 DALY (Disability-Adjusted Life Year)
DALY (Disability-Adjusted Life Year) is a measure of overall disease burden and is calculated as the sum of years of potential life lost due to premature death (YLL) and years lived with disability (YLD). The DALY takes into account both the quantity and quality of life lost due to disease or injury.
The YLL and YLD are components of the DALY, which are used to assess how diseases and injuries impact populations. As a result, @sec-01.2Components section provides a more comprehensive picture of the overall burden of disease by combining YLLs and YLDs in different life expectancy groups.
1.5 How the metrics are used
The health metrics of DALY, YLL, and YLD can be used in several ways to help prioritize public health interventions, evaluate the impact of diseases and injuries, and inform public health decision-making. Some common uses of these metrics include:
Prioritizing public health interventions: By calculating the overall burden of disease in a population, public health practitioners can prioritize which diseases and injuries to address first. This helps allocate resources and target interventions to the areas of greatest need.
Evaluating the impact of diseases and injuries: These metrics can be used to measure the impact of diseases and injuries on individuals and populations and to track changes over time. This information can help inform public health decision-making and allocate resources more effectively.
Comparing the burden of disease across populations: DALY, YLL, and YLD can be used to compare the burden of disease across populations and between different regions. This information can help identify disparities in health outcomes and inform targeted public health interventions.
Evaluating the effectiveness of public health programs: These metrics can be used to evaluate the impact of public health programs and to assess the effectiveness of public health interventions. This information can help public health practitioners identify areas for improvement and make necessary changes to ensure that programs are achieving their goals.
Monitoring global health trends: DALY, YLL, and YLD can also be used to monitor global health trends and track changes in the burden of disease over time. This information can be used to inform global health policies and allocate resources to address emerging health threats.
Overall, the health metrics of DALY, YLL, and YLD provide valuable information for public health practitioners, researchers, and policy makers to help prioritize and allocate resources, evaluate the impact of diseases and injuries, and inform public health decision-making.
1.6 HALE (Healthy Life Expectancy)
- Description and calculation