title: PROMIS Pediatric Anger Scale: an item response theory analysis.
abstract: OBJECTIVE
  The Patient-Reported Outcomes Measurement Information System (PROMIS) aims to develop patient-reported outcome (PROs) instruments for use in clinical research. The PROMIS pediatrics (ages 8-17) project focuses on the development of PROs across several health domains (physical function, pain, fatigue, emotional distress, social role relationships, and asthma symptoms). The objective of the present study was to report on the psychometric properties of the PROMIS Pediatric Anger Scale.
  
  
  METHODS
  Participants (n = 759) were recruited from public school settings, hospital-based outpatient, and subspecialty pediatrics clinics. The anger items (k = 10) were administered on one test form. A hierarchical confirmatory factor analytic model (CFA) was conducted to evaluate scale dimensionality and local dependence. Item response theory (IRT) analyses were then used to finalize the item scale and short form.
  
  
  RESULTS
  CFA confirmed that the anger items are representative of a unidimensional scale, and items with local dependence were removed, resulting in a six-item short form. The IRT-scaled scores from summed scores and each score's conditional standard error were calculated for the new six-item PROMIS Pediatric Anger Scale.
  
  
  CONCLUSIONS
  This study provides initial calibrations of the anger items and creates the PROMIS Pediatric Anger Scale, version 1.0.
authors.affiliation: Department of Epidemiology, CB #7295, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. dirwin@email.unc.edu
authors.forename: Debra E
authors.initials: DE
authors.lastname: Irwin
authors.forename: Brian D
authors.initials: BD
authors.lastname: Stucky
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Langer
authors.forename: David
authors.initials: D
authors.lastname: Thissen
authors.forename: Esi Morgan
authors.initials: EM
authors.lastname: DeWitt
authors.forename: Jin-Shei
authors.initials: JS
authors.lastname: Lai
authors.forename: Karin B
authors.initials: KB
authors.lastname: Yeatts
authors.forename: James W
authors.initials: JW
authors.lastname: Varni
authors.forename: Darren A
authors.initials: DA
authors.lastname: DeWalt
mesh_terms: D000293:Adolescent; D000786:Anger; D002648:Child; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D009657:North Carolina; D010361:Patients / Q000523:psychology*; D011594:Psychometrics; D011788:Quality of Life; D011795:Surveys and Questionnaires; D013781:Texas