Venous Blood-based Biomarkers in the China Health and Retirement Longitudinal Study (CHARLS): Rational, Design, and Results of the 2015 Wave.

Abstract

Blood biomarkers provide critical information about health of older population, especially in large developing countries where self-reports of health are often inaccurate due to lack of access to health care; however, it is very difficult to collect blood samples in representative population surveys in such countries. The China Health and Retirement Longitudinal Study (CHARLS), a nationally representative study of middle-aged and older Chinese, represents one of the first efforts to include blood biomarkers in a nationally representative survey of China. In the 2015 wave of CHARLS, 13,013 respondents located in 150 counties around China donated whole blood and assayed on a whole range of indicators. This paper describes the process of the sample collection, transportation, storage and analysis, and presents basic statistics.