Skip to main content

Table 3 Overall effect sizes and combined outcomes by different time points presented for studies reporting continuous and categorical measures

From: Effectiveness of school-based preventive interventions on adolescent alcohol use: a meta-analysis of randomized controlled trials

  Studies reporting continuous measures    Studies reporting categorical measures  
  K N g ¯ 95% CI Q df I 2 K N OR ¯ 95% CI Q df I 2
Overall effect size 12 16279 0.22** 0.08-0.36 184.11*** 11 94.03% 16 23010 0.94 0.85-1.04 38.08*** 15 60.61%
Alcohol use:               
 <3 months 8 6617 0.10** 0.03-0.17 10.66 7 34.35% 3 5763 1.18* 1.00-1.40 0.82 2 0.00%
  4-12 months 8 10479 0.27* 0.03-0.52 239.19*** 7 97.07% 11 16409 0.86* 0.75-0.99 29.57*** 10 66.18%
  >13 months 3 6617 0.37 −0.14-0.88 113.88*** 2 98.24% 10 18177 0.95 0.89-1.02 9.525 9 5.52%
  1. Note. Random effect model. k = number of studies; N = total number of participants; g ¯ = mean Hedges’g; OR ¯ = mean Odds Ratio; Q = test of heterogeneity; 95% CI = confidence interval; df = degrees of freedom; I2 = proportion of observed dispersion. *p < .05 **p < .01 ***p < .001.