From an original pool of 78,593 potential participants, 71,404 students were interviewed (response rate: 90.9%). However, data obtained from 7,520 (10.5%) respondents were omitted from the analysis due to missing information in regard to important questions (e.g., alcohol drinking, cigarette smoking, and sexual intercourse). Consequently, data obtained from 63,884 adolescents (32,417 males and 31,467 females) were available for analysis (age range: 13-19 years; mean age: 16.2 ± 1.7 years for both genders).
