A total of 14 studies were included in the review (n=3,512 participants). Sample sizes ranged from 10 to 1,705 participants. Eight studies were randomised and six were single group pre-post design studies. Loss to follow-up ranged from 0% to 57%.
Eight studies reported statistically significant positive behavioural changes, five reported statistically non-significant positive trends, and one reported no positive changes.
Six studies provided sufficient data to calculate effect sizes, which ranged from 0.09 to 1.38. According to Cohen's criteria, two of these studies showed small effects (0.2), two showed medium-sized effects (>0.5), and two showed large effects (>0.8).