summarizes the recruitment process for those participating in the “comprehensive” (full EDE assessment) and “abbreviated” (abbreviated EDE-Q assessment) phases of the project, respectively, as well as compares these individuals contacted through study outreach efforts to those who self-referred to the study. In both phases a minority of those contacted completed this initial screening (25% in comprehensive assessment phase, 14% in abbreviated assessment phase) yet there were few active refusals (<2% in both phases). The proportion of respondents who met initial eligibility based on their responses to binge eating questions was comparable in the two phases (16% in the comprehensive- and 18% in the abbreviated assessment phase) but substantially lower than those who self-referred to the study, 100% of whom met initial eligibility criteria. Although a larger proportion of those in the abbreviated assessment phase participated in the baseline assessment (80% for EDE-Q versus 45% when full EDE interview administered), the overall proportion from the two phases that were assessment eligible and randomized was similar (33% in comprehensive- phase versus 38% in abbreviated assessment phase). Interestingly, despite all of those who self-referred to the study meeting the initial eligibility criteria, a comparable more modest proportion of them (40%) were assessment eligible and randomized into one of the two studies. Only a small proportion of those initially contacted through study outreach about the potential opportunity to participate in the program to help gain control over eating (0.6% for comprehensive- and 0.7% for abbreviated assessment phase) were randomized into the trial in comparison to 28.7% of those who self-referred to the study.
Recruitment Process for All Modes of Recruitment
compares the characteristics of those participants initially identified for study outreach contact who responded to the screening by mail, online, and those who self-referred to the study across both trials. Those who self-referred were more likely to meet both thresholds for binge eating than were EMR-identified individuals (as shown from the NNT); specifically, for every two participants who were self-referrals, one more was expected to meet the study’s binge eating criteria than for every two individuals who responded either by mail or online). Among those reporting binge eating, those who self-referred reported modestly more ED-related impairment (77.65%) than those recruited through study outreach who responded either by mail (63.29%) or online (58.31%). There were also significant differences in the prevalence of obesity (BMI ≥ 30) in the different groups with a substantially larger proportion of those self-referred meeting obesity criteria (61%) than those study outreach participants responding by mail (34%). An intermediate prevalence of obesity (47%) was reported among those study outreach participants responding online. Self referred participants tended to report higher incomes than those reported by study outreach participants responding either by phone or online. There appeared to be no racial or ethnic differences between online, mail and self-referred respondents. Finally, although there were significant differences in the proportions of those with advanced education among the three groups, effect size estimates suggested that the differences were not meaningful.
Characteristics of those responding by mail, online, or self-referred (trials #1 and #2 combined)
Because second mailings of the eating disorders screening questionnaire to initial nonrespondents were only sent during the comprehensive assessment phase, is limited to those study outreach participants in trial #1. Modest differences were observed in the proportion of respondents meeting the stricter binge eating criteria (two times per week on average) with those responding more quickly reporting higher levels of binge eating. However, despite other differences in the groups that were statistically significant, effect size estimates suggested that the differences were not meaningful.
Characteristics of early and late responders to ED screener during comprehensive assessment case identification phase
Finally, shows the comparison of characteristics among those who met full study eligibility criteria and were randomized into either of the two trials. Those who self referred were younger on average and were more likely to report shape and weight concerns. However, there was no indication that the groups systematically varied by reported frequency of binge eating (one versus two times per week on average), perceived impairment related to disordered eating practices, rates of obesity, the likelihood of reporting dietary restraint nor other demographic characteristics.
Comparison of baseline characteristics of those randomized using study outreach (comprehensive and abbreviated ED assessments) to those self-referred for treatment