Reliability and validity of the Japanese version of the Yale‐Brown Obsessive‐Compulsive Scale

The reliability and validity of the Japanese version of the Yale‐Brown Obsessive‐Compulsive Scale (JY‐BOCS) were determined by 20 raters for 12 Japanese patients with obsessive compulsive disorder at four institutions. Interrater reliability for the total JY‐BOCS score was excellent, and the intraclass correlation coefficient was high (ICC = 0.960). Internal consistency was also excellent (Cronbach's α= 0.889). Concurrent and discriminant validity of the JY‐BOCS was examined by comparing the scores on the JY‐BOCS with those on the Maudsley Obsessional Compulsive Inventory (MOCI) and scales for depression and anxiety. A slight correlation was found between scores on the JY‐BOCS and MOCI, but no significant correlations were found between scores on the JY‐BOCS and those on scales for depression or anxiety.