title: Parent ratings of ADHD symptoms: generalized partial credit model analysis of differential item functioning across gender.
abstract: OBJECTIVE
  Generalized partial credit model, which is based on item response theory (IRT), was used to test differential item functioning (DIF) for the Diagnostic and Statistical Manual of Mental Disorders (4th ed.), inattention (IA), and hyperactivity/impulsivity (HI) symptoms across boys and girls.
  
  
  METHODS
  To accomplish this, parents completed an ADHD rating scale for 403 boys and 380 girls, between 6 and 11 years of age.
  
  
  RESULTS
  The findings indicated no DIF for all the slope parameters for both the IA and HI symptoms. For location parameters, there was no DIF for all the IA symptoms and for seven of the nine HI symptoms. However, the effect sizes for the DIF symptoms were small. Thus, there was good support for gender equivalency for the ADHD symptoms.
  
  
  CONCLUSIONS
  These findings extend existing data on gender equivalency of ADHD symptoms, obtained using other methodologies for testing measurement equivalency.
authors.affiliation: University of Tasmania, Tasmania, Australia. rapson.gomez@utas.edu.au
authors.forename: Rapson
authors.initials: R
authors.lastname: Gomez
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis*; D002648:Child; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D006948:Hyperkinesis / Q000175:diagnosis; D007175:Impulsive Behavior / Q000175:diagnosis; D008297:Male; D008960:Models, Psychological; D010290:Parents; D012720:Severity of Illness Index; D012737:Sex Factors; D011795:Surveys and Questionnaires