title: Measurement invariance of the PROMIS pain interference item bank across community and clinical samples.
abstract: OBJECTIVE
  This study examined the measurement invariance of responses to the patient-reported outcomes measurement information system (PROMIS) pain interference (PI) item bank. The original PROMIS calibration sample (Wave I) was augmented with a sample of persons recruited from the American Chronic Pain Association (ACPA) to increase the number of participants reporting higher levels of pain. Establishing measurement invariance of an item bank is essential for the valid interpretation of group differences in the latent concept being measured.
  
  
  METHODS
  Multi-group confirmatory factor analysis (MG-CFA) was used to evaluate successive levels of measurement invariance: configural, metric, and scalar invariance.
  
  
  RESULTS
  Support was found for configural and metric invariance of the PROMIS-PI, but not for scalar invariance.
  
  
  CONCLUSIONS
  Based on our results of MG-CFA, we recommend retaining the original parameter estimates obtained by combining the community sample of Wave I and ACPA participants. Future studies should extend this study by examining measurement equivalence in an item response theory framework such as differential item functioning analysis.
authors.affiliation: Department of Rehabilitation Medicine, University of Washington, Seattle, WA 98195, USA.
authors.forename: Jiseon
authors.initials: J
authors.lastname: Kim
authors.forename: Hyewon
authors.initials: H
authors.lastname: Chung
authors.forename: Dagmar
authors.initials: D
authors.lastname: Amtmann
authors.forename: Dennis A
authors.initials: DA
authors.lastname: Revicki
authors.forename: Karon F
authors.initials: KF
authors.lastname: Cook
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003625:Data Collection / Q000379:methods / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D004185:Disability Evaluation; D005006:Ethnicity / Q000706:statistics & numerical data*; D005163:Factor Analysis, Statistical; D005260:Female; D006304:Health Status; D006801:Humans; D007256:Information Systems; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods* / Q000706:statistics & numerical data; D010146:Pain / Q000503:physiopathology / Q000523:psychology*; D010147:Pain Measurement; D011594:Psychometrics / Q000379:methods*; D011788:Quality of Life; D015203:Reproducibility of Results; D055815:Young Adult