title: Analysis of the reliability and validity of the Turkish version of the intermittent and constant osteoarthritis pain questionnaire.
abstract: OBJECTIVE
  The aim of this study was to analyze the validity and reliability of the Turkish version (ICOAP-TR) of the intermittent and constant osteoarthritis pain (ICOAP) questionnaire in patients with knee osteoarthritis (OA).
  
  
  METHODS
  Thirty-eight volunteer patients diagnosed with knee OA answered the questionnaire twice with an interval of 2-4 days. The reliability of the measurement was assessed using Cronbach's alpha coefficient and intraclass correlation (ICC) for test-retest reliability. Criterion validity was tested against the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score and visual analog scale (VAS) designed to assess the perceived discomfort rated by the patient.
  
  
  RESULTS
  Test-retest reliability was found to be ICC=0.942 for total score, 0.902 for constant pain subscale, and 0.945 for intermittent pain subscale. Internal consistency was tested using Cronbach's alpha and was found to be 0.970 for total score, 0.948 for constant pain subscale, and 0.972 for intermittent pain subscale. For criterion validity, the correlation between the total score of ICOAP-TR and WOMAC pain subscale was r=0.779 (p<0.05), and correlation between total score of ICOAP-TR and VAS was r=0.570 (p<0.05).
  
  
  CONCLUSIONS
  The ICOAP-TR is a reliable and valid instrument to be used with patients with knee OA.
authors.affiliation: Pamukkale University School of Physical Therapy and Rehabilitation, Denizli, Turkey.
authors.forename: Suat
authors.initials: S
authors.lastname: Erel
authors.affiliation: Dokuz Eylül University School of Physical Therapy and Rehabilitation, İzmir, Turkey.
authors.forename: İbrahim Engin
authors.initials: İE
authors.lastname: Şimşek
authors.affiliation: Gülhane Military Medical Academy, Department of Orthopedics and Traumatology, Ankara, Turkey.
authors.forename: Hüseyin
authors.initials: H
authors.lastname: Özkan
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D007802:Language; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis*; D010146:Pain / Q000145:classification*; D010147:Pain Measurement / Q000379:methods*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D014177:Translations; D014421:Turkey