Table 1.
Overview of questionnaire items and response categories
| Variable | Questionnaire item | Item(s) handled | Response categories |
|---|---|---|---|
| Effect evaluation measures | |||
| Sitting time at school | On average, how long do you spend sitting during classes at school per day (do not include study time at home)? | Single item, recoded into a quantitative variable (min/day) using the midpoint method (e.g., ‘1–2 h’ = 90 min) | 1 = None, 2 = 1–15 min/day, 3 = 15–30 min/day, 4 = 30–60 min/day, 5 = 1–2 h/day, 6 = 2–3 h/day, 7 = 3–4 h/day, 8 = 4–5 h/day, 9 = 5–6 h/day, 10 = 6-7 h/day, 11 = More than 7 h/day (recoded into 420 min) |
| Number of breaks in sitting time at school | During a normal school lesson, how often do you usually stand up. stretch or walk around a bit? | Single item, recoded into a quantitative variable (times/h) | 1 = Never, 2 = Once, 3 = twice, 4 = three times, 5 = 4 times or more (recoded into 4) |
| Screen-time |
Roughly how many hours a day do you usually spend watching TV/DVD in your leisure time? (Weekdays and weekend days separately)
Roughly how many hours a day do you usually use a computer/games console for leisure activities? (Weekdays and weekend days separately) |
Separate items were recoded into quantitative variables (min/day) and following formula was used to assess screen-time: ((TV time + computer time on a weekday)*5) + ((TV time + computer time on a weekend day)*2), divided by 7. | 1 = None, 2 = Less than 30 min/day (recoded into 15 min), 3 = 30 min/day, 4 = 1 h/day, 5 = 1 h 30 min/day, 6 = 2 h/day, 7 = 2 h 30 min/day, 8 = 3 h/day, 9 = 3 h 30 min/day, 10 = 4 h or more per day (recoded into 4 h) |
| Preference to break up sitting time | I like breaking up the time I spend sitting. | Single item | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |
| Attitude towards breaking up sitting time | Breaking up the time I spend sitting is good for me. | Single item | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |
| Self-efficacy to break up sitting time | I find it hard to break up the time I spend sitting. | Single item | 1 = Strongly agree, 2 = Partly agree, 3 = Neither agree nor disagree, 4 = Partly disagree, 5 = Strongly disagree |
| Habit of breaking up sitting time | Breaking up the time I spend sitting is something that I do without even really thinking about it. | Single item | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |
| Relationship with classmates |
My classmates like being together
Most of my classmates are friendly and helpful My classmates accept me as I am |
Mean value of three items (Cronbach’s alpha at pre-, mid-, post-test = 0.68, 0.66 and 0.78) | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |
| Involvement in organising school activities | The pupils in our school are involved in organising school activities | Single item | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |
| Relationship with teachers | My classmates and me have good bonds with the teachers at school | Single item | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |
| Process evaluation measures | |||
| Frequency per week | How many times per week do you stand at the standing desk (From Monday to Friday)? | Single item, recoded into a quantitative variable (times/week) | 1 = Never (recoded into 0), 2 = Almost never (recoded into 0), 3 = 1 time a week, 4 = 2 times a week, 5 = 3 times a week, 6 = 4 times a week, 7 = once every day (recoded into 5), 8 = more than once every day (recoded into 10) |
| Duration a time | If you stand at the standing desk, how long a time do you stand up? | Single item, recoded into a quantitative variable (min/a time) | 1 = 1–15 min a time (recoded into 8 min), 2 = 16–30 min a time or half a lesson hour (recoded into 25 min), 3 = 31–45 min a time (recoded into 38 min), 4 = 46–60 min a time or an entire lesson hour (recoded into 50 min), 5 = more than 1 h a time (recoded into 60 min) |
| Preference to use the standing desk | I like taking lessons while standing at the standing desk | Single item | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |
| Self-efficacy to use the standing desk | I find it difficult to take lessons while standing at the standing desk | Single item | 1 = Strongly agree, 2 = Partly agree, 3 = Neither agree nor disagree, 4 = Partly disagree, 5 = Strongly disagree |
| Attitude towards using the standing desk | Taking lessons while standing at the standing desk is good for me | Single item | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |
| Habit of using the standing desk | Taking lessons while standing at the standing desk is something that I do without thinking about it. | Single item | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |
| Subjective norm related to using the standing desk | My classmates think it is good that I take lessons while standing at the standing desk | Single item | 1 = Strongly disagree, 2 = Partly disagree, 3 = Neither agree nor disagree, 4 = Partly agree, 5 = Strongly agree |