Table 1.
Background characteristics of students at pre-test in the intervention group and control group; cluster-randomized controlled intervention providing lessons on healthy food and changes to school vending machines in secondary schools in the Netherlands
| Intervention group (n 303) | Control group (n 311) | Total group (n 614) | ||||||
|---|---|---|---|---|---|---|---|---|
| Mean or n | sd or % | Missing | Mean or n | sd or % | Missing | Mean or n | sd or % | |
| Age (years)* | 13·7 | 0·7 | 5 | 13·5 | 0·7 | 5 | 13·6 | 0·7 |
| Sex (male)* | 124 | 40·9 | – | 154 | 49·5 | – | 278 | 45·3 |
| Ethnicity (native)** | 222 | 74·7 | 6 | 207 | 68·3 | 8 | 429 | 71·5 |
| Education* | – | – | ||||||
| Low | 171 | 56·4 | 143 | 46·0 | 314 | 51·1 | ||
| Middle | 88 | 29·0 | 70 | 22·5 | 158 | 25·7 | ||
| High | 44 | 14·5 | 98 | 31·5 | 142 | 23·1 | ||
| Grade 8 | 268 | 88·4 | – | 284 | 91·3 | – | 552 | 89·9 |
| BMI (kg/m2)* | 19·2 | 3·5 | 40 | 18·5 | 2·6 | 35 | 18·9 | 3·1 |
Data are presented as mean and standard deviation for age and BMI; otherwise as number and percentage.
*P<0·05; **P<0·10.