title: Injustice Experience Questionnaire, Japanese Version: Cross-Cultural Factor-Structure Comparison and Demographics Associated with Perceived Injustice.
abstract: OBJECTIVE
  The Injustice Experience Questionnaire (IEQ) assesses injury-related perceived injustice. This study aimed to (1) develop a Japanese version (IEQ-J), (2) examine its factor structure, validity, and reliability, and (3) discover which demographic variable(s) positively contributed to prediction of IEQ-J scores.
  
  
  METHODS
  Data from 71 patients (33 male, 38 female; age = 20+) with injury pain were employed to investigate factor structure by exploratory and confirmatory factor analyses. Concurrent validity was examined by Pearson correlation coefficients among the IEQ-J, Brief Pain Inventory (BPI), and Pain Catastrophizing Scale (PCS). Internal consistency was investigated by Cronbach's alpha, and test-retest reliability was indicated with intra-class correlations (ICCs) in 42 of 71 patients within four weeks. Relations between demographic variables and IEQ-J scores were examined by covariance analysis and linear regression models.
  
  
  RESULTS
  IEQ-J factor structure differed from the original two-factor model. A three-factor model with Severity/irreparability, Blame/unfairness, and Perceived lack of empathy was extracted. The three-factor model showed goodness-of-fit with the data and sufficient reliability (Cronbach's alpha of 0.90 for total IEQ-J; ICCs = 0.96). Pearson correlation coefficients among IEQ-J, BPI, and PCS ranged from 0.38 to 0.73. Pain duration over a year (regression coefficient, 11.92, 95%CI; 5.95-17.89) and liability for injury on another (regression coefficient, 12.17, 95%CI; 6.38-17.96) predicted IEQ-J total scores.
  
  
  CONCLUSIONS
  This study evidenced the IEQ-J's sound psychometric properties. The three-factor model was the latter distinctive in the Japanese version. Pain duration over a year and injury liability by another statistically significantly increased IEQ-J scores.
authors.affiliation: Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan.|Center for Pain Management, Osaka University Hospital, Suita-shi, Osaka, Japan.
authors.forename: Keiko
authors.identifier: http://orcid.org/0000-0002-4378-3290
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Center for Pain Management, Osaka University Hospital, Suita-shi, Osaka, Japan.|Department of Pain Medicine, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Adachi
authors.affiliation: Department of Pain Medicine, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan.|Department of Rehabilitation, Tanabe Orthopedics, Osaka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Mibu
authors.affiliation: Center for Pain Management, Osaka University Hospital, Suita-shi, Osaka, Japan.|Department of Nursing and Physical Therapy, Konan Women's University, Kobe, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Nishigami
authors.affiliation: Division of Anesthesiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Motoyama
authors.affiliation: Center for Pain Management, Osaka University Hospital, Suita-shi, Osaka, Japan.|Department of Anesthesiology & Intensive Care Medicine, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Uematsu
authors.affiliation: Center for Pain Management, Osaka University Hospital, Suita-shi, Osaka, Japan.|Department of Anesthesiology & Intensive Care Medicine, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Matsuda
authors.affiliation: Division of Anesthesiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Hitoaki
authors.initials: H
authors.lastname: Sato
authors.affiliation: Department of Mathematics, Keio University, Yokohama, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan.
authors.forename: Renzhe
authors.initials: R
authors.lastname: Cui
authors.affiliation: Division of Anesthesiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Takao
authors.affiliation: Center for Pain Management, Osaka University Hospital, Suita-shi, Osaka, Japan.|Department of Pain Medicine, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Shibata
authors.affiliation: Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iso
mesh_terms: D000328:Adult; D000368:Aged; D003431:Cross-Cultural Comparison; D003469:Culture; D003710:Demography; D005260:Female; D006801:Humans; D007564:Japan; D007802:Language; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods*; D010465:Perception; D011594:Psychometrics / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results; D012935:Social Justice / Q000523:psychology*; D011795:Surveys and Questionnaires / Q000592:standards; D014175:Translating; D055815:Young Adult