Disruptive Behavior Disorders Questionnaire (DBQ; Pelham et al., 1992). This scale includes all 8 DSM-IV-TR symptoms of ODD rated on a 0–3 Likert scale and is consistent with the 8 DSM-5 symptoms (APA, 2013). Two versions of the DBQ—parent (mother as informant) and teacher—were used as primary indicators of ODD. The mothers and teachers completed the DBQ independently. Although data were available for 969 children, both mother- and teacher-reports were available for 571 children, teacher-report only was available for 254 children, and mother-report only was available for 144 children. Inter-rater reliability for the two raters (n = 571) was r = .30, p < .001, ICC = .20; this magnitude is consistent with the moderate correlations typically found between mothers and teachers when rating child behaviors (Frick et al., 2010). The mother- and teacher-reports were combined by using the higher scoring response for each item, a common method for combining data from multiple informants (Bird et al., 1992; Piacentini et al., 1992). In the cases where only one informant’s report was available, the ratings from that informant (mother or teacher) were used. These combined ODD items were internally consistent in the current sample (α = .92).
