2024-08-20-世界卫生组织-WHO_methods_and_data_sources_for_life_tables_2000-2021_33页_505kb

Summary of WHO Methods and Data Sources for Life Tables 2000-2021

Core Content

The World Health Organization (WHO) has developed annual life tables for its Member States from 2000 to 2021, based on a combination of data sources and statistical methods. These life tables are essential for estimating global, regional, and country-level mortality patterns and trends, including all-cause and cause-specific mortality.

Main Approach

• Objective: Publish WHO annual period life tables for the years 2000-2021.
• Data Sources:
  • Vital Registration (VR): Used for countries with complete and reliable death registration data.
  • UN-IGME Estimates: Used for child mortality rates (under 15 years) in non-VR countries.
  • GBD2021 Data: Provided age-specific mortality rates and helped estimate mortality shocks.
  • Other Surveys and Censuses: Used for countries with incomplete VR systems.
• Methodology:
  • Abridged Life Tables: Used for most countries, with 5-year age groups starting from age 5.
  • Completeness Adjustments: Applied to VR data to account for underreporting.
  • Projection Models: Used for countries without complete VR data, including the Lee-Carter model for projecting mortality trends.
  • Uncertainty Quantification: Monte Carlo simulations were used to generate 1000 random draws from a normal approximation of the binomial distribution, with 95% uncertainty bounds defined by the 2.5th and 97.5th quantiles.

Key Adjustments

3.1 Updated Assessments of VR Completeness

• Child Mortality (under 15 years): Compared with UN-IGME estimates to assess completeness.
• Adult Mortality (15 years and over): Assessed using death distribution methods (DDMs) such as generalized growth balance (GGB), synthetic extinct generation (SEG), and a hybrid GGBSEG approach.
• Smoothing and Rescaling: For completeness estimates above 95%, values were capped at 100%. For those between 90% and 95%, they were rescaled using the formula:
  $$
  scaled\ completeness = 2 * estimated\ completeness - 0.9
  $$

3.2 Revision of Annual Death Rates

• High-Quality VR Countries: Used HMD data to validate and adjust mortality rates for older age groups.
• Smoothing for Small Populations: For countries with populations under 1 million, 3-year moving averages were used.
• Formula for m_x:
  $$
  m x = VR\ deaths / (VR\ population\ estimates) / (annual\ age-sex-specific\ completeness\ estimates)
  $$
• Mortality Shocks: For years without VR data, the Lee-Carter model was used to project mortality trends, and shock data (e.g., from GBD2021) were added back to account for events like the COVID-19 pandemic.

3.3 Quantification of Uncertainty

• Monte Carlo Simulation: Applied to completeness-adjusted VR data to generate 1000 random draws.
• Uncertainty Bounds: 95% uncertainty bounds were calculated using the 2.5th and 97.5th quantiles.

Infant and Child Mortality

• Mortality rates for infants and children aged 1-4 years were derived from UN-IGME estimates of IMR and U5MR.
• For ages 5-14 years, mortality rates were based on 5q5 and 10q5 estimates.
• Data sources include surveys, censuses, and VR systems, with UN-IGME providing the primary estimates for child mortality trends.

Mortality Shocks

• Natural Disasters: Estimated deaths from GBD2021, using EM-DAT/CRED data.
• Conflict Deaths: Estimated using data from UCDP, IISs, ACLED, GTD, and other sources.
• Exclusion of Other Causes: Deaths from non-war-related causes (e.g., infectious diseases, starvation) were not included in the conflict mortality estimates.

Life Expectancy and Healthy Life Expectancy

• Life Expectancy: Calculated using final age-sex-specific mortality rates for 2000-2021.
• Healthy Life Expectancy (HLE): Updated using WHO life tables and YLD estimates from GBD2021, with similar adjustments to disability weights and prevalence as before.
• Reporting: Life expectancies are published in World Health Statistics 2024, and full life tables are available in the WHO Global Health Observatory.

Data Sources and Methods

• VR Countries: 77 countries with at least 80% completeness of death registration data since 1990.
• Non-VR Countries: Use UN-IGME and GBD2021 data to estimate mortality rates.
• Special Cases:
  • Cyprus, Georgia, Moldova, Russia, Serbia: Exclude certain territories or provinces from VR data.
  • Singapore: Does not report deaths for non-citizen residents, which account for ~30% of the population.
  • Mauritius: Excludes Rodrigues Island from reported deaths.

References and Further Information

• WHO life tables and mortality estimates are available at:
  http://www.who.int/gho
  http://www.who.int/gho/mortality_burden_disease/en/index.html
• For more information, contact: healthstat@who.int

Annex Tables

• Annex Table A: Lists data sources and methods for each WHO Member State.
• Annex Table B: Provides estimated completeness of death registration data for the most recent year.