title: The therapeutic factor inventory-8: Using item response theory to create a brief scale for continuous process monitoring for group psychotherapy.
abstract: OBJECTIVE
  We tested a very brief version of the 23-item Therapeutic Factors Inventory-Short Form (TFI-S), and describe the use of Item Response Theory (IRT) for the purpose of developing short and reliable scales for group psychotherapy.
  
  
  METHODS
  Group therapy patients (N = 578) completed the TFI-S on one occasion, and their data were used for the IRT analysis. Of those, 304 completed the TFI-S and other measures on more than one occasion to assess sensitivity to change, concurrent, and predictive validity of the brief version.
  
  
  RESULTS
  Results suggest that the new TFI-8 is a brief, reliable, and valid measure of a higher-order group therapeutic factor.
  
  
  CONCLUSIONS
  The TFI-8 may be used for continuous process measurement and feedback to improve the functioning of therapy groups.
authors.affiliation: a Department of Psychology , The Ottawa Hospital - General Campus , Ottawa , ON , Canada.
authors.forename: Giorgio A
authors.initials: GA
authors.lastname: Tasca
authors.affiliation: b Department of Psychology , University of Ottawa , Ottawa , ON , Canada.
authors.forename: Christine
authors.initials: C
authors.lastname: Cabrera
authors.affiliation: b Department of Psychology , University of Ottawa , Ottawa , ON , Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kristjansson
authors.affiliation: c Department of Psychology , University of North Carolina at Charlotte , Charlotte , NC , USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: MacNair-Semands
authors.affiliation: d Department of Psychiatry , University of Alberta , Edmonton , AB , Canada.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Joyce
authors.affiliation: e Department of Psychiatry , University of British Columbia , Vancouver , BC , Canada.
authors.forename: John S
authors.initials: JS
authors.lastname: Ogrodniczuk
mesh_terms: D000328:Adult; D006801:Humans; D017064:Process Assessment, Health Care / Q000592:standards*; D011582:Psychological Theory; D011594:Psychometrics / Q000295:instrumentation*; D011615:Psychotherapy, Group / Q000592:standards*
keywords: group psychotherapy; item response theory; statistical methodology; test development; therapeutic factors