The Socio-demographic Index (SDI) is a composite metric developed by the Global Burden of Disease (GBD) Study to quantify a region or country's level of socio-demographic development.

SDI is calculated as the geometric mean of three indicators:

• Income per capita (lag-distributed)
• Average educational attainment (years of schooling among individuals aged 15+)
• Total fertility rate (TFR) among women under age 25

• Ranges from 0 (lowest development) to 1 (highest development)
• Enables categorization of countries/regions into:
  • High SDI
  • High–middle SDI
  • Middle SDI
  • Low–middle SDI
  • Low SDI

• To analyze how disease burden varies by socio-demographic status
• To provide a contextual framework for interpreting health outcomes and risk factor exposure
• To support comparative modeling across countries with different development levels

• Used extensively in GBD estimates of:
  • Mortality
  • Disability-Adjusted Life Years (DALYs)
  • Risk factor attribution
• Facilitates longitudinal and cross-country comparisons
• Supports projections of future health burden

• Regions with low SDI often have a higher burden of infectious diseases and maternal mortality.
• Regions with high SDI have a higher burden of non-communicable diseases (e.g., stroke, ICH), often with different risk factor profiles (e.g., aging, lifestyle, pollution).

• Global burden modeling
• SDI Region
• Disability-Adjusted Life Year (DALY)
• Intracerebral hemorrhage epidemiology