Table 2.
Baseline characteristics of participants and differences between the experimental and control groups at baseline.
| Variablea | Total N=2649 |
Experimental n=1622 |
Control n=1027 |
Baseline difference | P | ||
|
|
|
|
|
t (df) | χ2 (df) |
|
|
| Age (range 15-19 years), mean SD (missing=16) | 16.3 (1.2) | 16.0 (1.2) | 16.7 (1.2) | 15.01 (2633) |
|
<.001 | |
| Gender, n (%) (missing=11) |
|
|
|
|
38.6 (1) | <.001 | |
|
|
Male | 1395 (52.66) | 766 (47.23) | 629 (61.25) |
|
|
|
|
|
Female | 1243 (46.92) | 847 (52.22) | 396 (38.56) |
|
|
|
| Educational level, n (%) (missing=11) |
|
|
|
|
92.6 (1) | <.001 | |
|
|
High | 1546 (58.36) | 1056 (65.10) | 490 (47.71) |
|
|
|
|
|
Low | 1092 (41.22) | 557 (34.34) | 535 (52.09) |
|
|
|
| Religion, n (%) (missing=17) |
|
|
|
|
33.2 (4) | <.001 | |
|
|
Catholic | 610 (23.03) | 407 (25.09) | 203 (19.76) |
|
|
|
|
|
Protestant | 180 (6.79) | 133 (8.19) | 47 (4.58) |
|
|
|
|
|
Muslim | 165 (6.23) | 82 (5.06) | 83 (8.08) |
|
|
|
|
|
Other | 131 (4.95) | 81 (4.99) | 50 (4.87) |
|
|
|
|
|
No religion | 1546 (58.36) | 907 (55.92) | 639 (62.22) |
|
|
|
| Ethnicity, n (%) |
|
|
|
|
1.7 (1) | .19 | |
|
|
Dutch | 2326 (87.81) | 1434 (88.41) | 892 (86.85) |
|
|
|
|
|
Non-Dutch | 323 (12.19) | 188 (11.59) | 135 (13.15) |
|
|
|
| Alcohol use, n (%) |
|
|
|
|
|
|
|
|
|
Never | 710 (26.80) | 491 (30.27) | 219 (21.32) |
|
25.4 (1) | <.001 |
|
|
Binge drinking (missing=3) | 1343 (50.70) | 758 (46.73) | 585 (56.96) |
|
26.3 (1) | <.001 |
|
|
Excessive drinking (missing=18) | 245 (9.25) | 116 (7.15) | 129 (12.56) |
|
21.5 (1) | <.001 |
|
|
Weekly consumption, mean (SD) (missing=18) | 4.0 (9.4) | 3.4 (8.9) | 5.1 (9.9) | 4.57 (2631) |
|
<.001 |
| Parental participation |
|
|
|
|
|
|
|
|
|
Invited by adolescent, n |
|
199 | — |
|
|
|
|
|
Start, n (%) |
|
91 (45.7) | — |
|
|
|
|
|
End, n (%) |
|
76 (83.5) | — |
|
|
|
a Number of missing values per variable indicated as “missing.”