Development and Validation of a Decisional Balance Tool to Assess Perceived Benefits and Barriers of Vegetable Intake in Adults

OBJECTIVES: Inverse associations are observed between vegetable intake and diabetes, cardiovascular disease, cancer, and all-cause mortality. The decisional balance tool is a promotional tool targeting the perceived pros and cons of behavior adoption. The aim of this study was to develop and validate a decisional balance tool to assess the perceived benefits and barriers of vegetable intake in adults. METHODS: A total of 379 adults aged 20–70 years (mean age, 30.5 ± 12.6 years; male, 21.4%) were enrolled in this study. Demographic parameters (age, body mass index, marital status, employment status, house income, and family members), vegetable intake, stage of changes (precontemplation, contemplation, preparation, action/maintenance), the importance of change, and confidence (self-efficacy) were measured using a web-based survey. After constructing an initial item pool based on expert consultations and existing scales, Phase 1 of the study was launched, involving an exploratory factor analysis of 15 perceived benefits and 15 perceived barriers. The participants responded on a 5-point Likert scale. An exploratory factor analysis was conducted, and internal validity, external validity, and reliability were tested. Decisional balance was estimated by subtracting the barriers from the perceived benefits. RESULTS: The final 24 items had a two-domain structure in perceived benefits (“pleasure” and “healthy”) and a three-domain structure in perceived barriers (“not attractive,” “low priority,” and “hard to get”) with high internal consistency (Cronbach's alpha = 0.82, 0.79, 0.82, 0.76, and 0.76, respectively). The test–retest reliability study showed substantial values of the intraclass correlation coefficient (0.77). The perceived benefits score was positively correlated with vegetable servings, although the perceived barrier score was negatively correlated with vegetable servings (Spearman's correlation = 0.324 and −0.435, respectively). Significant and meaningful differences were observed between the stages of change in the pros and cons of vegetable intake (p for trend = 0.016). CONCLUSIONS: These findings suggest that this questionnaire is a valid, reliable tool for assessing the pros and cons of vegetable intake in adults. FUNDING SOURCES: JSPS KAKENHI.