title: A multidimensional measure of pain interference: reliability and validity of the pain disability assessment scale.
abstract: OBJECTIVE
  Measuring outcomes across multiple domains is essential for an adequate understanding of chronic pain and the effects of pain treatment. Pain interference reflects the negative effects of pain on functioning, and is recognized as a critical outcome domain. The Pain Disability Assessment Scale (PDAS) contains items that assess the negative effects of pain on broad spectrum pain interference domains. The purpose of this study was to examine the factor structure, reliability, and validity of the PDAS.
  
  
  METHODS
  One hundred sixty-four Japanese patients with chronic pain were administered the PDAS, the Brief Pain Inventory, and the Hospital Anxiety and Depression Scale.
  
  
  RESULTS
  The findings support a 3 factor structure of the PDAS items, as well as a high level of internal consistency of the scales created from these factors (Cronbach α's range: 0.87 to 0.95). Validity of the 3 scales was supported through their significant associations, in hypothesized directions, with measures of pain intensity, anxiety, depression, and another established measure of pain interference, as well as differences in PDAS scores between patients with versus without back pain.
  
  
  CONCLUSIONS
  The PDAS may be useful when researchers or clinicians require a multidimensional measure of the effects of pain on a patient's life.
authors.affiliation: Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University Hospital, 3-1-1 Maidashi, Higashiku, Fukuoka, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Yamashiro
authors.forename: Tatsuyuki
authors.initials: T
authors.lastname: Arimura
authors.forename: Rie
authors.initials: R
authors.lastname: Iwaki
authors.forename: Mark P
authors.initials: MP
authors.lastname: Jensen
authors.forename: Chiharu
authors.initials: C
authors.lastname: Kubo
authors.forename: Masako
authors.initials: M
authors.lastname: Hosoi
mesh_terms: D000328:Adult; D001007:Anxiety / Q000175:diagnosis / Q000209:etiology*; D002908:Chronic Disease; D003863:Depression / Q000175:diagnosis / Q000209:etiology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000150:complications* / Q000175:diagnosis* / Q000523:psychology; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000502:physiology; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D012189:Retrospective Studies