• cut-off point;
  • inventory;
  • oppositional defiant disorder;
  • sensitivity;
  • specificity

Abstract  The purpose of the present paper was to make a detailed examination of the cut-off point for the Oppositional Defiant Behavior Inventory (ODBI). The subjects were 56 untreated boys (age 6–15 years), who were diagnosed to have oppositional defiant disorder and who presented between December 2001 and March 2008. Controls were 690 boys with no history of contacting hospitals and no developmental or behavioral disorders at two elementary schools and two junior high schools in a city and its suburbs. It was shown that the level of opposition in boys could be evaluated regardless of the age groups by the ODBI, because there was no significant difference in the ODBI score for the one-way analysis of variance. Based on the sensitivity (88.2%), specificity (90.0%), positive predictive value (75.0%) and negative predictive value (95.7%), a score of 20 points was thus established as a suitable cut-off point to distinguish the children who are eligible for ODD diagnosis from those who are not.