Translation and validation of the German 12-Item Obsessive-Compulsive Inventory (OCI-12) in clinical and non-clinical samples [Author Accepted Manuscript]

Background: The Obsessive-Compulsive Inventory-Revised (OCI-R) is widely used to assess symptoms of Obsessive-Compulsive Disorder (OCD). Despite its consistent factor structure, criticism on its syndromal validity has been raised. With the recent update of the commonly used diagnostic manuals, hoarding symptoms are now better captured by the diagnosis “pathological hoarding”. Furthermore, the neutralising scale suffers from relatively low psychometric properties. Consequently, a 12-item version of the scale (OCI-12), excluding hoarding and neutralising items was recently developed in English. The current study examined the psychometric properties of the German version of the OCI-12. Methods: The psychometric properties of the translated German version of the OCI-12 were investigated in a German-speaking sample, consisting of 102 participants with OCD, 69 participants with an anxiety-related disorder, and 248 non-clinical controls. Results: The German version of the OCI-12 replicated the four-factor structure of the original English version, with a higher order factor of general OCD symptoms. In addition, similar to the original version, the German OCI-12 showed good internal consistency and test-retest reliability, moderate-to-good construct validity, and good-to-excellent diagnostic accuracy. Conclusion: The German version of the OCI-12 represents a syndromally valid and reliable inventory for assessing OCD symptoms. Psychometric properties are good-to-excellent and comparable to the original English version. The diagnostic sensitivity is good-to-excellent and further supports using the OCI-12 in clinical and research settings.