School food offer at lunchtime: assessing the validity and reliability of a web-based questionnaire

Abstract

Objectives To develop and validate a web-based self-diagnostic questionnaire on school food service offer aimed at food service managers (FSMs) by: i) identifying relevant indicators of school food offer, developing a questionnaire and validating the concept using an expert panel, ii) validating the questions by comparing the food service manager’s responses with observations by dietitians, and iii) undergoing a qualitative evaluation of the tool through direct observation and short interviews. Design Mixed methods. Setting Quebec, Canada. Participants Nine experts validated the theoretical constructs and indicators on which the questionnaire was based. Inter-rater reliability tests were conducted with 39 food service managers, who then participated in interviews about platform functionality satisfaction. Twenty school stakeholders participated in the survey pertaining to their use of the personalised report. Results The questionnaire focused on the main school food service’s lunchtime offer and comprised 26 questions. The overall strength of agreement was good, and all questions’ strengths of agreement were fair to excellent except for one question. Qualitative data reached saturation and showed that navigation through the questionnaire was fluid. Improvements were suggested to increase user-friendliness and simplicity of both the platform and questionnaire. Results from the survey showed that all respondents were either satisfied or very satisfied with their personalised report. Conclusions We successfully developed and validated a web-based self-diagnostic questionnaire. The final version facilitates knowledge mobilisation with school stakeholders and offers a new opportunity for the assessment and surveillance of school food offer.