Table 1: Baseline comparison of completers ( 𝑛 = 2 1 8 ) and attriters ( 𝑛 = 7 4 ).

CompletersAttriterst (chi-square test)P

% female59 63 (0.38).54
Mean Age (SD)25.80 (9.49) 24.75 (7.62) 0.95.34
% smokers11 16 (1.13).29
Mean cigarettes/day (SD)9.84 (12.04) 5.08 (3.18) 1.34.19
% use illicit drugs1731 (6.74).01
Mean drug use freq/month (SD) 8.00 (11.89)4.96 (5.55) 1.15.26
% drink alcohol74 71 (0.10).76
Mean drinks/week (SD) 5.57 (6.25) 6.25 (5.93) 0.71.48

Note. Average use figures were calculated only for participants who reported any use of the given substance.