Validity and Reliability of an Expanded Vegetable Questionnaire among Elementary School Children

Abstract

Background: The purpose of this study was to expand the School Physical Activity and Nutrition questionnaire to include a greater variety of vegetables and to evaluate the relative validity and reliability of these revised items. Objectives: This study utilized 2 convenience samples of third to fifth graders for an analysis: validity (n = 70) and reliability (n = 76). Validity was assessed by comparing questionnaire items with vegetable intake reported from a 24-hour dietary recall covering the same reference period. Reliability estimates were assessed via same-day test-retest. Results: Agreement correlations ranged from 0.35 to 0.71. Kappa statistics varied from 0.16 to 0.66. Percentage agreements ranged from 57% to 87%. Test-retest Spearman coefficients were greater than 0.50 for 6 items, weighted Kappa values were greater than 0.40 for all 7 items, and percentage agreement exceeded 75% for 5 items. Conclusions: Results suggest that the questionnaire is a valid and reliable measure of the previous day's vegetable intake in third- to fifth-grade students.