Accepted for/Published in: JMIR Formative Research
Date Submitted: Dec 25, 2023
Date Accepted: Mar 19, 2024
Examining and Comparing the Validity and Reproducibility of Scales to Determine the Variety of Vegetables Consumed
ABSTRACT
Background:
Previous studies reported that vegetable variety reduces the risk for non-communicable diseases independently of the amount consumed.
Objective:
This study aimed to examine and compare the validity and reproducibility of several scales to determine vegetable variety.
Methods:
This study aimed to examine and compare the validity and reproducibility of several scales to determine vegetable variety. Twenty-three nutrition students in Japan reported their vegetable intake over the past month using a self-administered questionnaire between July and August 2021. Four scales were used: 1) a single question regarding the number of vegetables consumed (Single); 2) a scale containing nine vegetable subgroups (Group); 3) a scale containing 19 vegetable items (Item-1); and 4) a scale containing 20 vegetable items (Item-2). Scale validity was assessed by correlation with the number of vegetable items collected from dietary records for seven consecutive days. Reproducibility was assessed by test-retest reliability.
Results:
A significant correlation was found of Item-1 and Item-2 (ρ = 0.51, 0. 44) with vegetable variety based on dietary records. Reproducibility showed a significant correlation in Group (ρ = 0.45) and strong correlations in Item-1 and Item-2 (ρ = 0.73, 0.75).
Conclusions:
The scales for vegetable items have good validity and reproducibility compared to the scales that utilized a single question or vegetable subgroup and, therefore, may determine the variety of vegetables consumed.
Citation
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