Sample

CHNS 1989 included 3,795 households. 3,616 households, 3,441 households, 3,875 households, and 4,403 households participated in CHNS 1991, CHNS1993, CHNS 1997 and CHNS 2000, respectively. All individuals in each household were surveyed in 1991, 1993, 1997 and 2000 for all data; however in 1989, health and nutritional data were only collected from preschoolers and adults aged 20-45.

CHNS 1989 surveyed 15,917 individuals. CHNS 1991 only surveyed individuals belonging to the original sample households which resulted in a total of 14,778 individuals. In CHNS 1993, all new households formed from sample households who resided in sample areas were added to this sample, resulting in a total of 13,893 individuals. In CHNS 1997, all newly-formed households who resided in sample areas and additional households to replace those no longer participating were added to the sample. New communities were also added to replace communities no longer participating, and Heilongjiang province replaced Liaoning province. A total of 14,426 individuals participated in 1997. In CHNS 2000, newly-formed households, replacement households, and replacement communities were again added, and Liaoning province returned to the study. A total of 15,648 individuals participated in 2000.