7th grade | 9th grade | 2nd grade (secondary school) | |||||||
---|---|---|---|---|---|---|---|---|---|
Boys % ( n) | Girls % ( n) | χ2( p) | Boys % ( n) | Girls % ( n) | χ2( p) | Boys % ( n) | Girls % ( n) | χ2( p) | |
High alcohol consumption | 3.7 (48) | 8.1 (109) | 22.62*** | 24.0 (298) | 25.9 (333) | 1.30 ns | 51.5 (620) | 47.5 (553) | 3.76 ns |
Everyday smoking | 2.1 (28) | 3.1 (43) | 2.54 ns | 8.0 (100) | 9.6 (124) | 2.07 ns | 9.1 (110) | 15.4 (181) | 22.33*** |
Used any illicit drug at least once | 4.5 (58) | 4.7 (63) | 0.021 ns | 12.3 (153) | 8.7 (112) | 8.61** | 22.7 (271) | 17.4 (201) | 10.25*** |