General and Eating Disorder Specific Flexibility: Development and Validation of the Eating Disorder Flexibility Index (EDFLIX) Questionnaire

Abstract

Findings from studies investigating cognitive flexibility in eating disorders (EDs) are inconsistent, and although neuropsychological tests are commonly used to measure these skills, they may not be particularly effective in predicting everyday functioning. Also, extant studies have largely focused on flexibility in anorexia nervosa (AN), with assessments targeting general rather than specific flexibility, and cognitive, rather than behavioral flexibility. Knowledge regarding ED specific flexibility and flexibility in bulimia nervosa (BN) and binge eating disorder (BED) is still scarce. The aim of this study was to develop and validate a novel measure assessing general and ED specific flexibility in a diagnostically diverse sample, and in healthy controls (HCs). A sample of 207 adult individuals with EDs (55% AN, 29% BN, 16% BED) and 288 HCs responded to an online, 51-item, pilot questionnaire on ED specific and general flexibility. In addition, participants completed the shift subscale from the Behavior Rating Inventory of Executive Function Adult version (BRIEF-A), and the Eating Disorder Diagnostic Scale (EDDS). A principal component analysis (PCA) in the clinical sample yielded a 36-item, three-factor solution capturing general flexibility, flexibility related to food and exercise , and flexibility concerning body shape and weight . Results showed that the measure had good to excellent internal consistency, and good convergent validity. A confirmatory factor analysis (CFA) using data from HCs revealed good fit indexes, supporting the original factor solution. A receiver operating characteristics analysis (ROC) demonstrated excellent accuracy in distinguishing scores from those with and without EDs. A cutoff score of 136 yielded the most balanced sensitivity and specificity. Significant differences in general and ED specific flexibility were found between individuals with and without EDs. Overall, HCs achieved the highest flexibility scores, followed by those with BED, BN, and AN. In sum this novel measure, the Eating Disorder Flexibility Index (EDFLIX) questionnaire, was found to be reliable and valid in the assessment of cognitive and behavioral flexibility, with results offering support for the conceptual distinction between general and ED related flexibility. The study also provides strong evidence for the discriminant validity of the EDFLIX with results revealing significant differences in flexibility in people with and without EDs. In addition, significant differences in flexibility also emerged when comparing diagnostic groups, indicating the utility of the assessment instrument for classification purposes.

Depressive symptoms rather than executive functioning predict group cognitive behavioural therapy outcome in binge eating disorder

“…The traditional neuropsychological tests may not be sensitive enough in detecting inefficiencies in executive functioning. Moreover, the tests were developed with the intent of assessing brain trauma and lesions, not psychiatric populations (Dahlgren, Hage, Wonderlich, & Stedal, 2019). However, also the baseline indexes of BRIEF‐A which measure executive functioning in daily life and are supposed to be more sensitive in detecting different levels of executive functioning (Rouel et al, 2016), failed to predict the speed of outcome in patients with BED.…”

Everyday flexibility and functional milestones in anorexia nervosa: survey results from a mixed community sample

“…Although cognitive flexibility is usually measured in AN with performance tests such as the Wisconsin Card Sort Test [16], self-reported flexibility scales have also been developed to improve the ecological validity of measurement by capturing the behavioral manifestations of cognitive issues as they occur in daily life. Disorderspecific scales include the Detail and Flexibility Questionnaire (DFlex; [33]), which assesses cognitive rigidity and attention to detail in daily life, and the Eating Disorder Flexibility Index (EDFLIX; [8]), which measures general and eating disorder-specific everyday flexibility. Although performance tests and self-report measures of cognitive flexibility appear to capture different aspects of the same construct [22], results in adolescent AN cohorts have demonstrated the utility of self-report data in observing associations between flexibility issues and functional outcomes which have proven difficult to identify with performance tests.…”

Cognitive inflexibility and over‐attention to detail: The Italian validation of the DFlex Questionnaire in patients with eating disorders

“…The first one evaluates the ability to exert control over thoughts and emotions, the second assesses the type of cognitive flexibility necessary to challenge and replace maladaptive thoughts with more adaptive ones and the third measures flexibility in interactions and communication style. Further, the newer Eating Disorder Flexibility Index Questionnaire (Dahlgren, Wiig‐Hage, Stedal, & Wonderlich, 2019) evaluates a flexibility concerning body shape and weight specifically in ED. Finally, the Autism Spectrum Quotient (AQ; Baron‐Cohen, Wheelwright, Skinner, Martin, & Clubley, 2001) evaluates the presence of autistic traits, including a subscale assessing difficulties in attention switching.…”