Page 32 - ON THE WAY TO HEALTHIER SCHOOL CANTEENS - Irma Evenhuis

Chapter 2. Study protocol
Canteen Scan (measured at T0 and T2)
Measure
Health level of the canteen (availability and accessibility of healthier food and drinks)
Response options
Multiple choice Open Question
Open Question Multiple choice
Concepts
Basic conditions for all canteens
Percentage of available healthier food and drinks on display
Percentage of available healthier food and drinks in vending machines.
The canteen’s accessibility criteria (to motivate people to select a healthier option)
Example
Encourages the school canteen people to drink water? (i.e. by water tap)
Please enter all products on display (at the counter, in display cases and on racks) in the school canteen
Please enter all products in the vending machine.
Does the school canteen present fruit or vegetables in an attractive manner?
a Asked for each implementation component.
b Only measured at T2.
c Only measured by the stakeholders of the intervention schools. d Also measured by logging the use digital.
Effect evaluation: The effectiveness of the implementation process will be evaluated by measuring at baseline and at follow-up after 6 months via 1) the self-reported purchase behaviour of students, and 2) the “health level” of the school canteen (Table 2.2).
The questionnaire to assess the primary outcome self-reported purchase behaviour of students, the behavioural determinants of purchase behaviour (Perceived behavioural control, attitude, and subjective norm of healthy eating in school) and the environmental determinants (like food brought from home, purchases during but outside school) is derived from existing validated Dutch questionnaires [103-107]. The frequency of food/ beverage purchases per week in the school canteen/vending machines of products that are the ‘healthier products’ and products which should be consumed only occasionally, will be asked [78, 79]. The questionnaire will be reviewed and discussed on face validity and content validity by all project members involved. Thereafter, it will be pretested by respondents of the same age as the target group using the cognitive interview method think- aloud [108]. The aim of this pre-test is to get insight into respondents’ comprehensibility and the length of the questionnaire, to be able to adapt questions if needed [108]. The questionnaire will be administered digitally in a classroom setting in the presence of a teacher or researcher.
The secondary outcome “health level” of the school canteen will be measured with the online tool, “the Canteen Scan”. This tool was developed and improved and improved in an iterative process through a collaboration of researchers, professionals, schools, caterers, and experts on nutrition and health behaviour, and tested on its validity and inter-rated reliability [100, 109]. The Canteen Scan checks to what extent a canteen meets the Guidelines for Healthier Canteens and subsequently provides tailored advice for improvements. The three parts of the guidelines can be entered in this tool: 1) a set of basic conditions for all canteens, 2) the food and drink available on display and in vending machines, and 3) the accessibility of healthier food and drink products [78, 100].
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