“…Twenty-one studies were excluded from the pooled analysis for the following reasons: the outcome of interest (percent of starters) was not reported (eight studies) [ 28 , 29 , 36 , 45 , 54 , 57 – 59 ], the data was not reported by gender (five studies) [ 27 , 30 , 39 , 53 , 60 ], the data was not in a usable format—the number of girls who started smoking was not reported by intervention group (six studies) [ 32 , 34 , 35 , 42 , 52 , 56 ], or they compared a mass media intervention combined with school intervention versus a school intervention alone, so their control group was not usual care (two studies) [ 50 , 51 ]. Therefore, of the 37 included studies (described in 43 articles), 16 were analyzed in the pooled analysis [ 16 , 17 , 26 , 31 , 33 , 37 , 38 , 40 , 41 , 43 , 44 , 46 – 49 , 55 ] (see Fig.…”