title: Psychometric validation of the Weiss Functional Impairment Rating Scale-Parent Report Form in children and adolescents with attention-deficit/hyperactivity disorder.
abstract: BACKGROUND
  Measurement properties of the Weiss Functional Impairment Rating Scale-Parent Report Form (WFIRS-P), which assesses attention-deficit/hyperactivity disorder (ADHD)-related functional impairment in children/adolescents (6-17 years), were examined.
  
  
  METHODS
  Data from seven randomized, controlled trials were pooled. Analyses were conducted in two random half-samples. WFIRS-P conceptual framework was evaluated using confirmatory factor analyses (CFA). Reliability was estimated using internal consistency (Cronbach's alpha) and test-retest reliability methods. Convergent validity was assessed using correlations between WFIRS-P domain scores and the ADHD-RS-IV and Clinical Global Impression-Severity (CGI-S) scales. Responsiveness was tested by comparing mean changes in WFIRS-P domain scores between responders and non-responders based on clinical criteria.
  
  
  RESULTS
  CFA adequately confirmed the item-to-scale relationships defined in the WFIRS-P conceptual framework. Cronbach's alpha coefficient exceeded 0.7 for all domains and test-retest reliability exceeded 0.7 for all but Risky Activities. With few exceptions, WFIRS-P domains correlated significantly (p < 0.05) with ADHD-RS-IV Total, Inattention and Hyperactivity-Impulsivity scores and CGI-S at baseline and follow-up in both random half-samples. Mean changes in WFIRS-P domain scores differed significantly between responder and non-responder groups in the expected direction (p < 0.001).
  
  
  CONCLUSIONS
  Study results support the reliability, validity and responsiveness of the WFIRS-P. Findings were replicated between two random samples, further demonstrating the robustness of results.
authors.affiliation: Shire, 725 Chesterbrook Boulevard, Wayne, PA, 19087, USA. kl_gajria@hotmail.com.
authors.forename: Kavita
authors.initials: K
authors.lastname: Gajria
authors.affiliation: QualityMetric Incorporated, 24 Albion Road, Building 400, Lincoln, RI, 02865, USA. mkosinski@qualitymetric.com.
authors.forename: Mark
authors.initials: M
authors.lastname: Kosinski
authors.affiliation: Shire, 725 Chesterbrook Boulevard, Wayne, PA, 19087, USA. vanja.x.sikirica@gsk.com.
authors.forename: Vanja
authors.initials: V
authors.lastname: Sikirica
authors.affiliation: Klinik für Kinder- und Jugendpsychiatrie und -psychotherapie, Universitätsmedizin der Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131, Mainz, Germany. michael.huss@unimedizin-mainz.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Huss
authors.affiliation: QualityMetric Incorporated, 24 Albion Road, Building 400, Lincoln, RI, 02865, USA. elayne_livote@uhc.com.
authors.forename: Elayne
authors.initials: E
authors.lastname: Livote
authors.affiliation: QualityMetric Incorporated, 24 Albion Road, Building 400, Lincoln, RI, 02865, USA. katpreilly@gmail.com.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Reilly
authors.affiliation: Paediatric Psychopharmacology, Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, D-68072, Mannheim, Germany. ralf.dittmann@zi-mannheim.de.
authors.forename: Ralf W
authors.initials: RW
authors.lastname: Dittmann
authors.affiliation: Shire, 725 Chesterbrook Boulevard, Wayne, PA, 19087, USA. herder@shire.com.
authors.forename: M Haim
authors.initials: MH
authors.lastname: Erder
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000523:psychology*; D002648:Child; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results