The Change in Eating Disorder Symptoms scale: scale development and psychometric properties.

Although several instruments provide reliable and valid diagnoses for eating disorders or measure specific features of eating disorders, existing instruments are limited in their ability to comprehensively assess session-by-session change in eating disorder symptoms during treatment. This study describes the initial development and psychometric properties of a scale designed to assess change in eating disorder symptoms during treatment, namely the Change in Eating Disorder Symptoms (CHEDS) scale. Two hundred and sixty-seven eating disordered and non-eating disordered participants completed the CHEDS and related measures. Item and factor analyses were conducted to select optimal items. Correlational analyses, group mean comparisons, and discriminant function analyses were conducted to examine the validity of the CHEDS. The CHEDS consisted of seven distinct symptom factors. The CHEDS total and subscale scores were significantly higher in eating disordered groups compared to non-eating disordered groups, and also differentiated eating disorder subtypes. Overall, results indicated that the CHEDS is a reliable and valid instrument. Studies addressing sensitivity to change and change indices for the CHEDS are forthcoming. 2009 Elsevier Ltd. All rights reserved.