“…In ten studies, the sample was school-based 16,17,18,19,20,21,22,23,24,25 and four included workers 26,27,28,29 . The sample size ranged from 160 individuals 30 to 54,369 8 , while the majority of the studies (38) included more than a thousand subjects, and only two included fewer than five hundred 30,31 .…”