Diet Screener in CHIS 2005: Validation Results
Risk Factor Monitoring & Methods Branch
staff have assessed the validity of the CHIS Diet Screener in the
Eating at America's Table Study (EATS)
and the Observing Protein
and Energy Nutrition Study (OPEN). In these studies, multiple 24-hour recalls in
conjunction with a measurement error model were used to assess validity. The screeners
used in these studies were similar but not identical to that used in CHIS 2005. We have
constructed similar questions from the data available and the scoring algorithms developed
specifically for CHIS. For added sugar, questions answered on the Diet History
Questionnaire administered in both studies were used as proxies for some of the screener
items.
Estimates of total Pyramid Servings of fruits and vegetables and teaspoons of added sugar in
EATS and OPEN are shown in the table below.
| |
Men (median intake) |
Women (median intake) |
| Recall |
Screener |
Recall |
Screener |
| Total fruits and vegetables (Pyramid servings) |
| EATS |
5.8 |
5.5 |
4.3 |
4.6 |
| OPEN |
6.2 |
5.3 |
5.2 |
4.7 |
| Total fruits and vegetables (cup equivalents) |
| EATS |
3.38 |
3.24 |
2.43 |
2.66 |
| OPEN |
3.60 |
3.13 |
3.09 |
2.75 |
| Added sugar |
| EATS |
17.5 |
18.1 |
12.3 |
11.7 |
| OPEN |
17.0 |
17.0 |
13.0 |
11.8 |
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 ethnic diets, including Asian
and possibly Latino populations.
At the individual level, correlations between the screener and estimated true intake
for servings of fruits and vegetables and added sugar are shown in the table below.
| |
Men |
Women |
| Total fruits and vegetables (Pyramid servings) |
| EATS |
0.67 |
0.49 |
| OPEN |
0.58 |
0.73 |
| Total fruits and vegetables (cup equivalents) |
| EATS |
0.70 |
0.52 |
| OPEN |
0.62 |
0.70 |
| Added sugar |
| EATS |
0.59 |
0.66 |
| OPEN |
0.69 |
0.66 |
Overall, about 25 to 50 percent of the variability in the true intake in fruit and
vegetable and added sugar 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 Dec;7(8):1097-105.
National estimates based on the 2000 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 Diet Assoc 2005 Mar;105(3):352-63.
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