Validity of Exercise Measures in Adults with Anorexia Nervosa: The EDE, Compulsive Exercise Test and Other Self-Report Scales.

Objective: Compulsive exercise is a prominent feature for the majority of patients with Anorexia Nervosa (AN), but there is a dearth of research evaluating assessment instruments. This study assessed the concurrent validity of the exercise items of the Eating Disorder Examination (EDE) and Eating Disorder Examination-Questionnaire (EDE-Q), with the Compulsive Exercise Test (CET) and other self-report exercise measures in patients with AN. We also aimed to perform validation of the CET in an adult clinical sample.

Methods: The sample consisted of 78 adults with AN, recruited for the randomized controlled trial "Taking a LEAP forward in the treatment of anorexia nervosa." At baseline, participants completed the EDE, EDE-Q, CET, Reasons for Exercise Inventory (REI), Commitment to Exercise Scale (CES) and Exercise Beliefs Questionnaire (EBQ). Correlational and regression analyses were performed.

Results: EDE exercise days and exercise time per day were positively correlated with each other and with all CET subscales (except Lack of exercise enjoyment), CES mean, EBQ total and REI total. Exercise time per day was associated with a higher EDE global score. The CET demonstrated good concurrent validity with the CES, the REI and the EBQ. Of the self-reports, the CET explained the greatest variance in eating disorder psychopathology and demonstrated good to excellent reliability in this sample.

Discussion: The EDE and EDE-Q demonstrated good concurrent validity with the CET. Further research is required to evaluate the CET's factor structure in a large clinical sample. However, the CET has demonstrated strong clinical utility in adult patients with AN. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2017; 50:533-541).