Gender differences on the Five to Fifteen questionnaire in a non-referred sample with inattention and hyperactivity-impulsivity and a clinic-referred sample with hyperkinetic disorder

Lambek, R., Trillingsgaard, A., Kadesjo, B., Damm, D. & Thomsen, P. H. (2010). Gender differences on the Five to Fifteen questionnaire in a non-referred sample with inattention and hyperactivity-impulsivity and a clinic-referred sample with hyperkinetic disorder. Scandinavian Journal of Psychology 51, 540–447. The aim of the present study was to examine gender differences in children with inattention, hyperactivity, and impulsivity on the Five to Fifteen (FTF) parent questionnaire. First, non-referred girls (n = 43) and boys (n = 51) with problems of attention and hyperactivity-impulsivity and then clinic-referred girls (n = 35) and boys (n = 66) with hyperkinetic disorder (HKD) were compared on the FTF. Results suggested that non-referred boys were more hyperactive-impulsive than non-referred girls, whereas clinic-referred boys and girl with HKD were more similar than dissimilar on the FTF questionnaire. Secondly, it was examined whether the application of gender mixed norms versus gender specific norms would result in varying proportions of clinic-referred children with HKD being identified as impaired on the subdomains of the FTF questionnaire. Based on results it was concluded that the use of a gender mixed normative sample may lead to overestimation of impairment in boys with HKD, but the type of sample applied to define impairment on the FTF should depend on the purpose for applying the questionnaire.