Hypochondriasis Y-BOCS: A Study of the Psychometric Properties of a Clinician-Administered Semi-Structured Interview to Assess Hypochondriacal Thoughts and Behaviours

Introduction: This study investigated the psychometric properties of the first clinician-administered semi-structured interview for assessing the severity of hypochondriacal symptoms. The Hypochondriasis Yale-Brown Obsessive-Compulsive Scale (H-YBOCS) consisted of three a priori dimensions: hypochondriacal obsessions, compulsions and avoidance. Methods: The 16-item interview was conducted with 112 participants with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, hypochondriasis. We analysed factor analytic structure, reliability, construct validity and sensitivity to change. Results: Factor analysis supported a three-factor model similar to the a priori dimensions. Internal consistency ranged from satisfactory to good. Inter-rater reliability was excellent. The construct validity was low to moderate. The H-YBOCS was sensitive for measuring changes in symptom severity. Conclusion: The H-YBOCS is a (factorially) valid and coherent interview with a high level of agreement across different raters. The relatively low discriminant validity could be due to co-morbid anxiety and depressive disorders. Overall, the H-YBOCS seems to be a promising contribution to the assessment of hypochondriasis. Copyright (C) 2009 John Wiley & Sons, Ltd.