Table 1 Prevalence of drinking and sociodemographic variables at 16 years by sex
 Males Females % (95% CI) % (95% CI) Occasions of consuming four or more drinks in a row in the previous 2 weeks n = 2530 n = 3479 Nil 64 (63 to 66) 70 (68 to 71) 1 15 (14 to 17) 14 (13 to 16) ⩾ 2 (defined as binge drinking) 20 (19 to 22) 16 (15 to 17) Habitual frequency of alcohol consumption in last year n = 2569 n = 3512 Every day 2 (1 to 3) 1 (1 to 2) Four or five times per week 4 (3 to 5) 4 (3 to 4) Two or three times per week 20 (18 to 21) 16 (15 to 17) About once per week 30 (28 to 32) 28 (26 to 29) About once per month 15 (13 to 16) 13 (12 to 15) Special occasions only 21 (19 to 22) 29 (28 to 31) Never drink 9 (8 to 10) 9 (8 to 10) Alcohol consumed in the previous week (units) n = 2342 n = 3084 0 33 (31 to 35) 40 (38 to 41) 1–4 27 (25 to 29) 35 (34 to 37) 5–9 18 (17 to 20) 16 (15 to 17) 10–14 10 (9 to 12) 5 (5 to 6) 15 or more 12 (10 to 13) 4 (3 to 5) Father’s social class at 16 years n = 3387 n = 3783 I or II 36 (34 to 37) 34 (32 to 35) III A or B 46 (45 to 48) 48 (46 to 49) IV or V or others 18 (17 to 20) 19 (17 to 20) Maternal education n = 3068 n = 3455 Achieved A levels or higher degree 22 (20 to 23) 20 (19 to 21)