Author Sample size Method(s) of data analysis Attrition at end of study Length of treatment Length of followup (i.e., months after treatment completion) Mellin et al. [34 ] 66 Not clear; presumably completers only 16% 3 months 12 months Jiang et al. [35 ] 75 Completers only 8% 24 months None Coates et al. [36 ] 31 Not clear; presumably completers only None reported 20 weeks 9 months Brownell et al. [37 ] 42 Not clear; presumably completers only 14% 16 months (sessions were held every 2 months after the initial 16 weekly sessions) None Wadden et al. [38 ] 47 Completers only 34% 4 months 6 months Coates et al. [39 ] 42 ITT, in which return to baseline weight was assumed for participants who did not provide data 14% 20 weeks 6 months Resnicow et al [40 ] 147 (1) ITT (unclear how missing data were handled), and (2) inclusion of only those participants who completed at least 75% of treatment sessions 27% 6 months 6 months Ebbeling et al. [41 ] 16 ITT, in which return to baseline weight was assumed for participants who did not provide data (completers analysis also reported in paper, with same result) 13% 6 months 6 months Gutin et al. [42 ] 80 (1) Completers only and (2) inclusion of only those participants who attended at least 40% of treatment sessions and at least two sessions per week of physical activity 29% 8 months None Jelalian et al. [43 ] 76 (1) Completers only and (2) ITT, in which return to baseline weight was assumed for participants who did not provide data 26% 4 months 6 months Williamson et al. [44 ] 57 ITT with LOCF (authors also noted that same results were found with completers analyses) 30% 24 months None Doyle et al. [45 ] 80 (1) Completers only and (2) ITT, in which return to baseline weight was assumed for participants who did not provide data 17% 4 months 4 months Jones et al. [46 ] 105 (1) Completers only and (2) ITT, in which return to baseline weight was assumed for participants who did not provide data 17% 4 months 5 months Chanoine et al. [47 ] 539 Modified ITT: inclusion of all randomized participants who completed at least one postbaseline visit, with LOCF for subsequent missing data 35% 12 months None Ozkan et al. [48 ] 42 Completers only 17% Mean
1
1
.
7
±
3
.
7
months None
