title: Development of a crosswalk for pain interference measured by the BPI and PROMIS pain interference short form.
abstract: BACKGROUND
  To help researchers in multiple sclerosis (MS) take advantage of the measurement properties of the PROMIS Pain Interference instrument while maintaining continuity with previous research, we developed and tested a crosswalk table to transform Brief Pain Inventory pain interference scale (BPI-PI) scores to PROMIS-PI short form (PROMIS-PI SF) scores.
  
  
  METHODS
  The BPI-PI and the PROMIS-PI SF were administered in two studies that included persons with MS. One sample of 369 participants served as a developmental calibration sample, and a separate sample of 360 served as a validation sample. The crosswalk development included dimensionality assessment, item-level parameter estimation, and assessment of accuracy. BPI-PI and PROMIS-PI T scores were obtained from participants' item responses, and using the crosswalk table, PROMIS-PI T scores were derived from responses to the BPI-PI items. Differences between observed and crosswalked T scores were compared in both samples.
  
  
  RESULTS
  For BPI-PI summary scores ranging from 0 to 10, corresponding T scores ranged from 38.6 to 81.2. The mean difference between observed and crosswalked T scores was 0.51 (SD = 3.9) in the calibration sample and -1.47 (SD = 4.2) in the validation sample. Approximately 80 % of crosswalked scores in the calibration sample were within four score points of the observed PROMIS-PI SF scores, and 70 % were within four points in the validation sample. In both samples, the largest differences were at lower levels of the pain interference continuum.
  
  
  CONCLUSIONS
  Crosswalked pain interference scores adequately approximated observed PROMIS-PI SF scores in both the calibration and validation samples. MS researchers and clinicians interested in adopting the PROMIS instruments can use this table to transform BPI-PI scores to enable comparisons with other studies and to maintain continuity with previous research.
authors.affiliation: Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Askew
authors.forename: Jiseon
authors.initials: J
authors.lastname: Kim
authors.forename: Hyewon
authors.initials: H
authors.lastname: Chung
authors.forename: Karon F
authors.initials: KF
authors.lastname: Cook
authors.forename: Kurt L
authors.initials: KL
authors.lastname: Johnson
authors.forename: Dagmar
authors.initials: D
authors.lastname: Amtmann
mesh_terms: D059350:Chronic Pain / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000150:complications*; D059408:Pain Management; D010147:Pain Measurement / Q000295:instrumentation*; D011594:Psychometrics / Q000706:statistics & numerical data; D011788:Quality of Life; D011795:Surveys and Questionnaires
references.citation: Qual Life Res. 2011 Nov;20(9):1497-505
references.pmid: 21384264
references.citation: Pain. 1996 Oct;67(2-3):267-73
references.pmid: 8951920
references.citation: Disabil Health J. 2012 Jul;5(3):177-84
references.pmid: 22726858
references.citation: Pain. 2004 May;109(1-2):103-9
references.pmid: 15082131
references.citation: J Clin Epidemiol. 2010 Nov;63(11):1179-94
references.pmid: 20685078
references.citation: Qual Life Res. 2013 Apr;22(3):501-7
references.pmid: 22552604
references.citation: J Clin Epidemiol. 2011 May;64(5):507-16
references.pmid: 21447427
references.citation: Qual Life Res. 2012 Sep;21(7):1123-33
references.pmid: 22048931
references.citation: N Engl J Med. 1994 Mar 3;330(9):592-6
references.pmid: 7508092
references.citation: Mult Scler. 2003 Dec;9(6):605-11
references.pmid: 14664474
references.citation: Pain. 2003 Dec;106(3):337-345
references.pmid: 14659516
references.citation: Pain. 2010 Jul;150(1):173-182
references.pmid: 20554116