The feasibility of questionnaire-based instruments is generally high in epidemiological studies and several instruments have been developed in order to measure the perceived physical demands in the working environment [ 7- 10].
Comparing projects one and two, the feasibility of questionnaires may be increased through opting for only electronic administration to keep costs lower, and through modifying 'off the shelf' questionnaires where they are available.
In structured focus group interviews following a predefined check-list, the pupils were asked for their general opinion about the questionnaire, the comprehensibility and feasibility of the questionnaire and their opinion about the design of the questionnaire.
A telephone interview with the parents was conducted following a checklist in order to assess the parents' general opinion about the questionnaire, the comprehensibility and feasibility of the questionnaire and their opinion about its design.
Subsequently, they were interviewed by telephone about how the questions could be improved for content or phrasing, about the comprehensibility and feasibility of the questionnaire and about the design of the questionnaire.
After the consultation, interviews were held with the patients to identify problems with the readability and feasibility of the questionnaire, resulting in some small textual adjustments to the questionnaire.
The response rate, average time of filling out the questionnaire and proportions of missing values were used as indicators of feasibility of the questionnaire.
To test the feasibility of the questionnaire, we will evaluate response rates and the time required to complete the questionnaire.
As with any performance measure, the validity, reliability and feasibility of a questionnaire are important to investigate and establish [ 14, 36], particularly where the results of the questionnaire are used for employment decisions or performance appraisals.
