Evaluating brief measures of fruit and vegetable consumption frequency and variety: cognition, interpretation, and other measurement issues.

Overview

To evaluate whether items from 3 brief measures of fruit and vegetable consumption were understood and interpreted as intended, cognitive testing was conducted in a purposive sample of 31 white, African-American and Hispanic persons. The measurement instruments tested were the fruit and vegetable module from the Behavioral Risk Factor Surveillance System (to measure frequency), and 1 fruit and 1 vegetable variety measurement instrument developed by the investigators. The cognitive testing interviews were analyzed qualitatively to identify interpretation difficulties and other measurement issues. The testing identified a number of measurement issues, including issues related to time frame, wording, interpretation, grouping of items, and serving size. Recommendations based on the findings were incorporated into revised versions of each instrument, which were further tested in a small sample. As revised and presented in this article, these instruments for assessing fruit and vegetable frequency and variety appear to be understood and interpreted as intended across different racial and ethnic groups, and may be useful in situations requiring brief dietary assessment, although further testing is needed.