Objective:
To develop and evaluate an instrument to assess severity in anorexia nervosa (AN), the Clinician Administered Staging Instrument for Anorexia Nervosa (CASIAN).
Method:
Candidate items for the CASIAN were developed in three phases (domain, content, and item generation) followed by a pilot study. The psychometric properties of the resultant 34‐item questionnaire were investigated in cross‐sectional and longitudinal samples (N = 171) with DSM‐IV AN and subthreshold AN.
Results:
Item and factor analysis procedures resulted in a refined 23‐item CASIAN comprising of six factors (“Motivation,” “Weight,” “Illness Duration,” “Obsessionality,” “Bulimic Behaviors,” and “Acute Issues”). The CASIAN had high internal consistency (.811), test–retest (.957), and interrater reliability (.973). Preliminary support for the convergent, discriminant, concurrent, and predictive validity of the CASIAN was found.
Discussion:
The CASIAN is a psychometrically sound instrument. Further studies are needed to confirm the factor structure and assess its clinical and research utility. © 2011 by Wiley Periodicals, Inc. (Int J Eat Disord 2012)