title: Composite Pain Index: Reliability, Validity, and Sensitivity of a Patient-Reported Outcome for Research.
abstract: OBJECTIVE
  A single score that represents the multidimensionality of pain would be an innovation for patient-reported outcomes. Our aim was to determine the reliability, validity, and sensitivity of the Composite Pain Index (CPI).
  
  
  METHODS
  Methodological analysis of data from a randomized controlled, pretest/post-test education-based intervention study.
  
  
  METHODS
  The study was conducted in outpatient oncology clinics.
  
  
  METHODS
  The 176 subjects had pain, were 52 ± 12.5 years on average, 63% were female, and 46% had stage IV cancers.
  
  
  METHODS
  We generated the CPI from pain location, intensity, quality, and pattern scores measured with an electronic version of Melzack's McGill Pain Questionnaire.
  
  
  RESULTS
  The internal consistency values for the individual scores comprising the CPI were adequate (0.71 baseline, 0.69 post-test). Principal components analysis extracted one factor with an eigenvalue of 2.17 with explained variance of 54% at baseline and replicated the one factor with an eigenvalue of 2.11 at post-test. The factor loadings for location, intensity, quality, and pattern were 0.65, 0.71, 0.85, and 0.71, respectively (baseline), and 0.59, 0.81, 0.84, and 0.63, respectively (post-test). The CPI was sensitive to an education intervention effect.
  
  
  CONCLUSIONS
  Findings support the CPI as a score that integrates the multidimensional pain experience in people with cancer. It could be used as a patient-reported outcome measure to quantify the complexity of pain in clinical research and population studies of cancer pain and studied for relevance in other pain populations.
authors.affiliation: Department of Biobehavioral Health Science, University of Illinois, Chicago College of Nursing Chicago, Illinois, USA.|University of Illinois Cancer Center, Chicago, Illinois, USA.
authors.forename: Diana J
authors.initials: DJ
authors.lastname: Wilkie
authors.affiliation: University of Illinois Cancer Center, Chicago, Illinois, USA.|Division of Hematology/Oncology, University of Illinois, Chicago College of Medicine, Chicago, Illinois, USA.|Jesse Brown Veteran's Administration Medical Center, Chicago, Illinois.|Department of Biopharmaceutical Sciences, University of Illinois, Chicago College of Pharmacy, Chicago, Illinois, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Molokie
authors.affiliation: Department of Biobehavioral Health Science, University of Illinois, Chicago College of Nursing Chicago, Illinois, USA.
authors.forename: Marie L
authors.initials: ML
authors.lastname: Suarez
authors.affiliation: Department of Biobehavioral Health Science, University of Illinois, Chicago College of Nursing Chicago, Illinois, USA.
authors.forename: Miriam O
authors.initials: MO
authors.lastname: Ezenwa
authors.affiliation: University of Illinois Cancer Center, Chicago, Illinois, USA.|Department of Biopharmaceutical Sciences, University of Illinois, Chicago College of Pharmacy, Chicago, Illinois, USA.
authors.forename: Zaijie J
authors.initials: ZJ
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods* / Q000706:statistics & numerical data; D063868:Patient Outcome Assessment; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
keywords: Interventional; Pain Management