The Fruit & Vegetable Screener in the 2000 California Health Interview Survey: Validation Results
Risk Factor Assessment Branch staff have assessed the validity of the CHIS Fruit and Vegetable Screener in the Eating at America's Table Study (EATS). In this study, multiple 24-hour recalls in conjunction with a measurement error model were used to assess validity. The screeners used in the EATS included additional foods and reported portion sizes. For comparison of the CHIS screener, we have used the similar questions in EATS and the scoring algorithms developed specifically for CHIS.
In EATS, estimates of median intake of Servings of Fruits and Vegetables were: Men: recalls - 5.8; screener - 5.5; Women: recalls - 4.2; screener - 4.5. These validation results suggest that dietary exposure estimates computed for the CHIS may be useful to compare subgroup means, especially for populations consuming mainstream diets. The estimates may be less useful for populations with more ethnic diets, including Asian and possibly Latino populations.
At the individual level, correlations between the screener and estimated true intake were 0.68 for men and 0.49 for women; about 25 to 50 percent of the variability in the true intake will be captured by the screener questions. Thus, although significant error may be associated with these estimates of diet, we believe the exposure estimates still substantially reflect what individuals are actually consuming.
Validation results for the Multifactor Screener, which includes a similar fruit and vegetable component, are reported in detail in:
- Thompson FE, Midthune D, Subar AF, Kahle LL, Schatzkin A, Kipnis V. Performance of a short tool to assess dietary intakes of fruits and vegetables, percentage energy from fat and fibre. Public Health Nutr 2004;7(8):1097-106.
National estimates based on the NHIS Multifactor Screener are presented and compared with other national data in:
- Thompson FE, Midthune D, Subar AF, McNeel T, Berrigan D, Kipnis V. Dietary intake estimates in the National Health Interview Survey, 2000: Methodology, results, and interpretation. J Am Dietet Assoc 2005;105:352-63.