Design and sample characteristics of the 2005-2008 Nutrition and Health Survey in Taiwan

The Nutrition and Health Survey in Taiwan (NAHSIT) 2005-2008 was funded by the Department of Health to provide continued assessment of health and nutrition of the people in Taiwan. This household survey collected data from children aged less than 6 years and adults aged 19 years and above, and adopted a three-stage stratified, clustered sampling scheme similar to that used in the NAHSIT 1993-1996. Four samples were produced. One sample with five geographical strata was selected for inference to the whole of Taiwan, while the other three samples, including Hakka, Penghu and mountainous areas were produced for inference to each cultural stratum. A total of 6,189 household interviews and 3,670 health examinations were completed. Interview data included household information, socio-demographics, 24-hour dietary recall, food frequency and habits, dietary and nutritional knowledge, attitudes and behaviors, physical activity, medical history and bone health. Health exam data included anthropometry, blood pressure, physical fitness, bone density, as well as blood and urine collection. Response rate for the household interview was 65%. Of these household interviews, 59% participated in the health exam. Only in a few age subgroups were there significant differences in sex, age, education, or ethnicity distribution between respondents and non-respondents. For the health exam, certain significant differences between participants and non-participants were mostly observed in those aged 19-64 years. The results of this survey will be of benefit to researchers, policy makers and the public to understand and improve the nutrition and health status of pre-school children and adults in Taiwan.