title: Differential item functioning of the patient-reported outcomes information system (PROMIS®) pain interference item bank by language (Spanish versus English).
abstract: About 70% of Latinos, 5 years old or older, in the United States speak Spanish at home. Measurement equivalence of the PROMIS®pain interference (PI) item bank by language of administration (English versus Spanish) has not been evaluated.
  
  
  
  A sample of 527 adult Spanish-speaking Latinos completed the Spanish version of the 41-item PROMIS®pain interference item bank. We evaluate dimensionality, monotonicity and local independence of the Spanish-language items. Then we evaluate differential item functioning (DIF) using ordinal logistic regression with item response theory scores estimated from DIF-free "anchor" items.
  
  
  
  One of the 41 items in the Spanish version of the PROMIS®PI item bank was identified as having significant uniform DIF.
  
  
  
  English- and Spanish-speaking subjects with the same level of pain interference responded differently to 1 of the 41 items in the PROMIS®PI item bank. This item was not retained due to proprietary issues. The original English language item parameters can be used when estimating PROMIS®PI scores.
authors.affiliation: UCLA Division of General Internal Medicine and Health Services Research, Department of Medicine, 911 Broxton Avenue, Los Angeles, CA, 90095-1736, USA. shpaz@ucla.edu.
authors.forename: Sylvia H
authors.identifier: 0000-0001-7477-1703
authors.initials: SH
authors.lastname: Paz
authors.affiliation: UCLA Division of General Internal Medicine and Health Services Research, Department of Medicine, 911 Broxton Avenue, Los Angeles, CA, 90095-1736, USA.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Spritzer
authors.affiliation: UCLA Department of Psychology, Franz Hall, 502 Portola Plaza, Los Angeles, CA, 90095, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Reise
authors.affiliation: UCLA Division of General Internal Medicine and Health Services Research, Department of Medicine, 911 Broxton Avenue, Los Angeles, CA, 90095-1736, USA.|RAND, 1776 Main Street, Santa Monica, CA, 90407, USA.
authors.forename: Ron D
authors.initials: RD
authors.lastname: Hays
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D007256:Information Systems; D007802:Language; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology*; D000071066:Patient Reported Outcome Measures; D011594:Psychometrics; D011788:Quality of Life; D014481:United States
keywords: Item response theory; Language DIF; PROMIS®; Patient-reported outcomes; Psychometrics