Evaluating empirically valid and clinically meaningful change in specialized inpatient treatment for severe eating disorders

Introduction: Eating disorders (EDs) often exhibit poor treatment outcomes, high rates of relapse or treatment dropout, and elevated rates of comorbid medical complexities (Friedman et al., 2016), posing significant challenges for both the researchers and treating clinicians. Despite guidelines for the treatment of this clinical population recommend that individuals with the most severe eating disorder symptoms and co-occurring emotional disorders receive treatment in intensive care settings such as residential, multimodal, and multidisciplinary programs (Thompson-Brenner et al., 2018), empirical evidence are still scarce. One reason is that widely used criteria for treatment response in severe EDs are typically focused primarily on the statistically-significant reduction of psychopathological symptomatology, thus not considering whether or not the observed post-test level of functioning falls outside the range of the dysfunctional population (Schlegl et al., 2016). The aim of the present study was to evaluate the clinical relevance of change in an intensive inpatient treatment for EDs using a combination of clinical significance (CS) and the Reliable Change Index (RCI) (Wise, 2004). Thereby, we aimed to classify patients into four specific treatment outcome groups: patients who have deteriorated, remained unchanged, made a reliable improvement and made a clinically significant improvement. Methods: A national sample of eating disorder (ED) patients (N=112) were assessed at intake, at 1-month and at treatment termination on measures of ED symptoms, such as the Eating Attitudes Test-40 (EAT-40), the Eating Disorder Inventory-3 (EDI-3), and Body Uneasiness Test (BUT), as well as psychiatric symptoms, such as Beck Depression Inventory-II (BDI-II), and the Symptom Checklist-90-Revised (SCL-90-R). The inclusion criteria were: (a) aged at least 18 years; (b) a pre-treatment diagnoses of either DSM-IV-TR/DSM-5 anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), or otherwise specified feeding and eating disorders (OSFED) posed by a licensed staff psychologist or psychiatrist and based on the Structured Clinical Interview for DSM disorders (SCID); (c) presenting no organic syndromes, psychotic disorder, or syndrome with psychotic symptoms that could complicate the assessment of any variable in the study. No limits were applied to the body mass index (BMI) at the admission. Treatment was provided in a multidisciplinary clinical inpatient setting and consisted in individual weekly psychotherapy sessions, encounters with specialized social workers, and sessions with a nutritional physician. Results: Findings showed a statistically significant symptom reduction, with moderate to large effect sizes, especially on overall eating disorder and depressive symptoms severity, even when controlling for treatment length. Moreover, the majority of patients showed both reliable and clinically significant symptomatic improvement at discharge. Regarding differences between treatment outcome groups, we found that patients with clinically significant improvement were suffering from less overall and depressive symptomatology at intake. Conclusion: These findings suggest the beneficial effects of intensive and multidisciplinary residential treatment setting for patients with severe EDs (Thompson-Brenner, 2015). This kind of treatment intervention might be highly recommended for individuals with EDs who are medically stable but have severe symptoms or comorbidities that interfere with treatment at less intensive levels of care. Furthermore, considering multiple indices of symptomatic change enables a more clinically useful perspective of treatment outcomes in this clinical population (Björk et al., 2011). In an effort to increase treatment responsiveness and effectiveness, future studies should continue to evaluate the clinical significance of therapeutic change obtained by these types of treatment programs in wide samples of individuals with severe EDs.