Validation of the <scp>ED</scp> ‐15‐ <scp>NL</scp> , a Brief Session‐by‐Session Questionnaire to Measure Changes in Eating Disorder Cognitions and Behaviors

ABSTRACT Objective The Eating Disorder‐15 ( ED ‐15) questionnaire measures core symptoms of eating disorders ( EDs ) and is used to track session‐by‐session symptom change during treatment. The ED ‐15 was found to have good validity and reliability with a two‐factor structure in the original English version, as well as in the Portuguese, Spanish, and Turkish versions. The aim of the current study was to examine the psychometric qualities and factor structure of the Dutch version of the ED ‐15 ( ED ‐15‐ NL ). Method Fifty‐nine patients with an ED (currently receiving CBT‐T treatment) and 513 non‐clinical controls completed a set of questionnaires, including measures pertaining to ED‐pathology (ED‐15‐NL, and Eating Disorder Examination Questionnaire; EDE‐Q), anxiety (Generalized Anxiety Disorder‐7; GAD‐7), and depressive symptoms (Patient Health Questionnaire‐9; PHQ‐9). Results The ED ‐15‐ NL provided evidence supporting the originally two‐factor structure, good concurrent validity (i.e., strong correlations with the EDE ‐Q) and good divergent validity (i.e., differentiated well between EDs , and between symptoms of depression and anxiety). The ED ‐15‐ NL also provided evidence supporting excellent reliability (i.e., internal consistency, test‐retest reliability) and high sensitivity to change. Discussion The findings show preliminary support for the reliability and validity of ED ‐15‐ NL scores for session‐by‐session assessment of changes in ED ‐symptoms, despite the relatively small clinical sample. The ED ‐15‐ NL therefore represents not only a valuable tool for clinical practice, but also a useful instrument for scientific research.