Evaluating Evidence-Based Interventions in Low Socio-Economic-Status Populations.

Objective
Socio-economic-status (SES) has rarely been reported or investigated in eating disorders (EDs) research. This Research Forum considers, from various perspectives, how SES may impact on evaluating evidence-based treatments for EDs.

Method
We first reviewed previous literature that informs how SES impacts prevalence of EDs, help-seeking, and treatment outcome. We then present findings from a case series effectiveness study of an early intervention program in low SES areas for EDs and discuss implications about the impact of SES on the effectiveness of evidence-based interventions. Finally, we examine barriers to conducting rigorous evaluations in this population and discuss directions for future treatment outcome research.

Results
Evidence suggests a higher level of disordered eating but less help seeking in lower SES groups. In our case series, 96 participants started treatment and completed a mean of 13.85 sessions, 84 (87.5%) completed a mean of 6.40 sessional measures on ED cognitions and behaviors, but only 31% completed more extensive pre-treatment and post-treatment measures. The completer effect size decrease for the global Eating Disorder Examination-Questionnaire score was 2.05 (95% CI: 1.43, 2.68) commensurate with other effectiveness studies in mixed SES groups. The high rates of missing data related to more extensive assessment present a barrier to evaluating evidence-based treatments in this population.

Discussion
Evidence from the present study revealed individuals from low SES can achieve similar treatment outcomes to other populations when receiving evidence-based ED treatment. Future studies should investigate a range of approaches to maximizing data collection, including use of shorter sessional measures.