Using shape and weight overvaluation to empirically differentiate severity of other specified feeding or eating...

Although no severity specifiers are noted in the Diagnostic and Statistical Manual of Mental Disorders - 5 for other specified feeding or eating disorder (OSFED), shape/weight overvaluation is a proposed eating disorder (ED) severity specifier. We used structural equation modeling (SEM) Trees to empirically determine values of shape/weight overvaluation that differentiate OSFED severity. We additionally tested whether the SEM Tree-defined thresholds or a clinical cutoff for shape/weight overvaluation differentiated severity more meaningfully.

Participants were 690 females with OSFED presenting to residential ED treatment. SEM Tree analyses specified an outcome model of OSFED severity and then recursively partitioning the outcome model into severity groups. The SEM Tree-defined and clinical cutoff severity groups were compared on clinical characteristics.

SEM Trees identified one split that occurred at value 5.12 on our shape/weight overvaluation items from the Eating Disorder Examination Questionnaire. The subgroup with higher overvaluation had significantly greater intensity of ED and depressive symptoms and longer lengths of stay. The subgroups created from the shape/weight overvaluation clinical-cut off value of 4 differed on the same clinical characteristics as the SEM Tree-derived groups, with the exception of laxative use frequency. Effect sizes were larger for the clinical cutoff as compared to the SEM Tree severity specification scheme.

These cross-sectional data were used from a predominately white and female residential treatment sample; this likely skewed the subgroups and may limit generalizability.

Shape/weight overvaluation can meaningfully differentiate OSFED severity. The clinical cutoff slightly outperformed the empirically determined thresholds for shape/weight overvaluation.