Are Adolescent Treatment Studies of Eating Disorders Utilizing Clinically Relevant Samples? A Comparison of RCT and Clinic Treatment-Seeking Youth with Eating Disorders

Eating disorders (ED) are a public health concern associated with significant morbidity and mortality (Jacobi et al., 2004, Keel et al., 2003). Early identification and treatment is therefore critical (Le Grange and Loeb, 2007). Despite the negative physical and psychosocial health outcomes associated with EDs, treatment is underutilized (Vitiello and Lederhendler, 2000, Fairburn et al., 1993) and clinical trials often have difficulties with recruitment and retention (Halmi et al., 2005). Some investigators argue that research findings are not always generalizable to community populations (Kazdin, 2008) because study participants must meet pre-defined inclusion criteria. This may be particularly important in ED research, as many patients are diagnosed with eating disorder not otherwise specified (EDNOS) (Eddy et al., 2008) and hence might not qualify for studies with rigid entry criteria based on diagnostic categories. Research studies often have utilized manualized treatments with specified numbers of sessions and time course of treatment (Westen et al., 2004) which might dissuade potential participants with greater psychopathology or comorbidities from enrolling. If this were the case, randomized controlled trial (RCT) samples would be skewed toward those with less severe psychopathology and the results obtained might not be generalizable to patients with more complex presentations (Godart et al., 2007, Humphreys and Weisner, 2000). However, at least one study suggests that most clinic outpatients would meet inclusion criteria for a prior published RCT (Stirman et al., 2003). This finding has been supported by ED research reporting more similarities than differences among adult clinic and research samples in terms of symptom severity, but not in demographic features (e.g., age, level of education) (Wilfley et al., 2001). It is important to better understand how fee-for-service clinic and research samples compare for purposes of recruitment, as well as to gain more insight into the generalizability of research findings to clinic samples. To our knowledge, no research has compared children and adolescents with EDs seeking outpatient treatment through a fee-for-service clinic or RCT. The purpose of the current study was to fill this gap in the literature by comparing demographic, eating-related, and psychosocial characteristics of an adolescent sample with EDs that are clinic treatment-seeking (CTS) or research treatment-seeking through an RCT. We hypothesized that, consistent with previous research in the adult ED field (Wilfley et al., 2001), differences in demographics would be found between the two groups. Specifically, we expected that CTS participants would have a higher family income than RCT participants, given that the RCTs offering treatment for this sample are at no-cost to participants. We also hypothesized that, consistent with previous findings (Stirman et al., 2003, Wilfley et al., 2001), the two groups would not significantly differ in terms of eating-related or general psychopathology, but that the CTS sample would be more likely to have a comorbid diagnosis, as this might not be addressed in an RCT or such patients might be excluded from RCTs. As there could be differences in samples during a recruitment period for an RCT compared to usual practice, we conducted a secondary analysis comparing adolescents randomized to an RCT to those who presented for treatment during the recruitment window for an RCT and met inclusion criteria for an RCT, but opted to receive fee-for-service treatment.