Development of the County-Level Social Deprivation Index 2020 and Its Association With Health Outcomes in China.

Objective: The lack of an up-to-date area deprivation index for China is a major barrier to health inequality monitoring and evaluation in the world's most populous country. This study aimed to develop the County-Level Social Deprivation Index 2020 for China from the most recent census data and analyze its relation to health outcomes.

Methods: On the basis of the 2020 census data, 14 indicators for 2844 counties were selected across 5 domains, including income, employment, housing, education, and urban-rural location. The index was created using principal component analysis with oblique rotation. Associations between deprivation quintile groups and life expectancy and infant mortality were examined, with extensive sensitivity analyses around alternative indicators and weighting methods.

Results: The new deprivation index was based on a weighted sum of 3 components that altogether explained 74% of the variation in the 14 indicators. Counties in the Eastern region tended to be less deprived, whereas counties in the Southwestern region tended to be more deprived. The life expectancy was 4.51 years shorter, and the infant mortality was 5.18% higher for counties in the most deprived quintile than those in the least deprived quintile. The grouping result and the association with the health outcomes were consistent across the primary and sensitivity analyses.

Conclusions: The County-Level Social Deprivation Index 2020 for China reveals a clear social gradient in life expectancy and infant mortality across deprivation quintile groups. It can be used to help monitor health inequalities, identify high-need populations and quantify health inequality impacts in China.