Baseline characteristics of participants by randomised group (n=741)
| Characteristic | Intervention n=390 (52.6%) | Control n=351 (47.4%) | p Value |
|---|---|---|---|
| Age (years) mean (MD) (SD) | 16.15 (16) (0.77) | 16.06 (16) (0.73) | 0.800* |
| Sex | <0.001† | ||
| Female | 239 (61.4) | 146 (41.6) | |
| Male | 150 (38.6) | 205 (58.4) | |
| Education | 0.117† | ||
| Theoretical programme | 172 (44.1) | 176 (50.1) | |
| Vocational programme | 218 (55.9) | 175 (49.9) | |
| Immigrant background‡ | 0.017† | ||
| Yes | 123 (31.5) | 83 (23.6) | |
| No | 267 (68.5) | 268 (76.4) | |
| Educational level, mother§ | 0.799¶ | ||
| University | 167 (54.9) | 158 (53.7) | |
| Upper secondary school | 118 (38.8) | 118 (40.1) | |
| Elementary school | 19 (6.3) | 18 (6.1) | |
| Educational level, father§ | 0.334¶ | ||
| University | 100 (36.2) | 112 (39.9) | |
| Upper secondary school | 145 (52.5) | 142 (50.5) | |
| Elementary school | 31 (11.2) | 27 (9.6) | |
| Main occupation, mother | 0.148† | ||
| Employed** | 339 (87.1) | 315 (90.5) | |
| Unemployed†† | 50 (12.9) | 33 (9.5) | |
| Main occupation, father | 0.095† | ||
| Employed** | 331 (92.5) | 318 (92.5) | |
| Unemployed†† | 27 (7.5) | 15 (4.5) | |
| Tobacco use (smoking) | 0.197† | ||
| Never | 316 (81.0) | 297 (84.6) | |
| Occasionally/daily | 74 (19.0) | 54 (15.4) | |
| Tobacco use (snuff) | 0.767† | ||
| Never | 359 (92.1) | 321 (91.5) | |
| Occasionally/daily | 31 (7.9) | 30 (8.5) | |
| Alcohol consumption | 0.284† | ||
| Never | 257 (66.1) | 218 (62.3) | |
| Occasionally/monthly/weekly | 132 (33.9) | 132 (37.7) | |
| HPV vaccinated (only girls‡‡‡) | 0.103† | ||
| Yes | 126 (52.7) | 89 (60.9) | |
| No | 83 (34.9) | 47 (32.4) | |
| Do not know | 29 (12.2) | 9 (6.2) | |
*Independent samples t test. †χ2 tests.
‡Immigrant background: born outside Sweden or one or two parents born outside Sweden.
§Total amount do not add up to n=741 (100%) due to do not know, not presented and/or missing answer. ¶Mann-Whitney Test. **Employed includes studying and/or parental leave. ††Unemployed includes sick leave and similar.
‡‡‡Not included in the numbers: 1 boy in CG HPV vaccinated at baseline.
HPV, human papillomavirus.