Validation of an instrument for perceived factors affecting fruit and vegetable intake based on Pender's health promotion model.

Abstract

Increasing fruit and vegetable (F&V) intake has a protective role against chronic conditions such as cardiovascular disease, cancer and diabetes. The present study aimed to validate an instrument for measuring the perception of effective factors on consumption behaviour of F&V based on Pender's health promotion model (HPM).This cross-sectional validation survey has consisted of five steps: literature review in order to plan and develop an instrument, face validity assessment, content validity assessment, reliability assessment and construct validity assessment with the cooperation of experts in health education, nutritionists and the target group (government employees). In the present study, reliability and validity of constructs were determined through Cronbach's alpha and exploratory factor analysis, respectively, in SPSS 22. The mean impact score was acceptable for 96·42 % of items in face validity. The mean scores of content validity ratio (CVR), content validity index (CVI) and reliability were 0·92, 0·97 and 0·96, respectively. According to the principal component analysis with varimax rotation, 104 items were identified in 15 factors contributing to 61·17 % of the model cumulative variance. Given the favourable scores of the research instrument in face validity, content validity and reliability as well as its ability to predict the extracted factors from the model, it can be used as a suitable instrument in future studies.