2 47 The effectiveness of Take it Personal! on substance use Table 2 Fixed effects parameters of linear mixed-effects models assessing intervention effectiveness on different outcome variables. Condition Time Condition × Time Outcome variable n df dn df F p dn df F p dn df F p Substance use frequency+± 1 54.52 0.33 0.744 0.94 5.33 0.279 50.43 9.27 0.004** Alcohol use frequency 1 42.09 0.25 0.618 0.61 1.96 0.485 48.53 4.15 0.047* Cannabis use frequency 1 63.11 2.13 0.149 0.95 0.98 0.509 54.54 13.56 <0.001*** Other drug use frequency 1 60.66 0.58 0.458 1.12 1.18 0.448 54.95 2.88 0.096 Substance use severity+± 1 42.09 1.81 0.357 0.39 22.87 0.366 42.09 2.20 0.145 Alcohol use severity 1 45.14 4.28 0.044* 1.22 3.32 0.284 48.26 5.37 0.025* Drug use severity 1 45.02 0.55 0.462 0.38 6.55 0.463 42.09 1.22 0.275 Binge drinking+ 1 50.04 1.23 0.600 1.17 1.00 0.491 48.02 8.63 0.005** Note. * p< .05. ** p< .01. *** p< .001. + The three primary outcome variables. ± The frequency/severity of each adolescent’s most frequently/severely used substance at baseline. Condition is the between-subject factor distinguishing those in intervention and control condition. Kenward-Roger approximation for degrees of freedom was used. n df = numerator degrees of freedom. dn df = denumerator degrees of freedom.
RkJQdWJsaXNoZXIy MTk4NDMw