Measure | N initiate behavior | N current behavior | Childhood < 11 y | Early 11 to 13 y | Mid 14 to 16 y | Late 17 to 18 y | p-valueb |
---|---|---|---|---|---|---|---|
Males | |||||||
Smoking | 719 | 278 | 18 (44%) | 130 (52%) | 115 (53%) | 15 (29%) | 0.01 |
Alcohol use | 537 | 300 | 2 (33%) | 132 (59%) | 109 (72%) | 57 (56%) | 0.02 |
Illicit drug use | 273 | 89 | NA | 4 (33%) | 22 (22%) | 62 (64%) | < 0.01 |
Sexual activity | 577 | 222 | NA | 40 (52%) | 135 (54%) | 47 (41%) | 0.05 |
Females | |||||||
Smoking | 649 | 140 | 8 (50%) | 37 (25%) | 71 (27%) | 24 (23%) | 0.15 |
Alcohol use | 521 | 210 | 2 (18%) | 62 (38%) | 85 (49%) | 61 (42%) | 0.05 |
Illicit drug use | 133 | 30 | NA | 1 (11%) | 7 (16%) | 21 (37%) | 0.04 |
Sexual activity | 629 | 293 | NA | 3 (50%) | 136 (61%) | 154 (52%) | 0.10 |