Objective: This study used the mean and covariance structures analysis approach to examine the equality or invariance of ratings of the 18 ADHD symptoms. Method: 783 Australian and 928 Malaysian parents provided ratings for an ADHD rating scale. Invariance was tested across these groups (Comparison 1), and North European Australian (n = 623) and Malay Malaysian (n = 571, Comparison 2) groups. Results: Results indicate support for form and item factor loading invariance; more than half the total number of symptoms showed item intercept invariance, and 14 symptoms showed invariance for error variances. There was invariance for both the factor variances and the covariance, and the latent mean scores for hyperactivity/impulsivity. For inattention latent scores, the Malaysian (Comparison 1) and Malay Malaysian (Comparison 2) groups had higher scores. Conclusion: These results indicate fairly good support for invariance for parent ratings of the ADHD symptoms across the groups compared. (J. of Att. Diss. 2009; 12(5) 422-433)
Item response theory (IRT) based differential item functioning (DIF) was used to examine the construct and normative invariance of the DSM-IV oppositional defiant disorder (ODD) symptoms for ratings across Malaysian and Australian children, and Malaysian Malay and Malaysian Chinese children. To accomplish these goals, parents completed the Disruptive Behavior Rating Scale, which includes the eight DSM-IV ODD symptoms. Although the comparisons involving Malaysian and Australian children indicated DIF for five symptoms, only the symptom for “touchy” showed notable DIF. This was also the only symptom that showed DIF for the comparisons involving Malay and Chinese children. There were also minimal differences in the latent mean scores across Australian and Malaysian children and also Malay and Chinese children. These results indicate good support for the construct and normative invariance of the ODD symptoms for the samples compared.