ABSTRACT
BACKGROUND: The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) is a widely used semi structured clinician-rated interview to assess the presence and severity of obsessive-compulsive disorder (OCD). The scale is revised (Y-BOCS-II) to overcome several psychometric limitations, for example by extending the scoring for better discrimination within higher severity levels. AIM: To examine the responsiveness and other psychometric properties of the Y-BOCS-II in a Dutch clinical sample. METHOD: The Y-BOCS-II was translated into Dutch (Y-BOCS-II) and administered to 110 patients seeking therapy for OCD. This was done twice, before and after treatment. The original Y-BOCS was simultaneously rated. Self-report measures regarding depression, symptom severity and OCD symptoms were assessed. RESULTS: The Y-BOCS-II had a good internal consistency (Cronbach’s α = 0.84), test-retest (ICC = 0.81) and inter-rater reliability (ICC = 0.94). The construct validity proved to be modest to good. The responsiveness over time was in favour of the Y-BOCS-II, compared with the YBOCS-I, particularly in the severely affected OCD patients. CONCLUSION: The Y-BOCS-II severity scale is a reliable and valid instrument for accurately assessing the severity of OCD symptoms and for measuring treatment-induced change. This second version also has clinical and psychometric advantages over the YBOCS-I. When these findings are sufficiently replicated, use of the YBOCS-II as the new common standard seems recommendable.
