Responsiveness and other psychometric properties of the Yale-Brown Obsessive-Compulsive Scale Severity Scale-Second Edition in a Dutch clinical sample

The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) is a widely used 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. The aim of the present study was to examine the responsiveness and other psychometric properties of the Y-BOCS-II Severity Scale in a Dutch clinical sample. The Y-BOCS-II is translated into Dutch 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. The Y-BOCS-II has a good internal consistency (Cronbach's alpha = 0.84), test-retest (intraclass correlation coefficient [ICC] = 0.89) and interrater reliability (ICC = 0.98). The construct validity proved to be modest to good. The responsiveness over time was in favour of the Y-BOCS-II, compared with the Y-BOCS-I, particularly in the moderate-severely affected OCD patients. 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 Y-BOCS-I. When these findings are sufficiently replicated, use of the Y-BOCS-II as the new common standard seems recommendable.

Automated summary

The present study examined the responsiveness and other psychometric properties of the revised Y-BOCS-II Severity Scale in a Dutch clinical sample. The results showed good internal consistency, test-retest reliability, and interrater reliability for the scale. The construct validity was also modest to good. The Y-BOCS-II was found to be more responsive over time compared to the original Y-BOCS-I, particularly in moderately to severely affected OCD patients.