title: Self-reported disability according to the International Classification of Functioning, Disability and Health Low Back Pain Core Set: Test-retest agreement and reliability.
abstract: BACKGROUND
  The International Classification of Functioning, Disability and Health (ICF) Low Back Pain Core Set (LBP-CS) has been proposed as a tool to facilitate the description and measurement of chronic low back pain (CLBP) related disability. Patient ratings of ICF categories may serve as a practical and effective method for acquiring patient input on activity limitations and participation restrictions.
  
  
  OBJECTIVE
  To investigate the test-retest agreement and reliability of patient ratings of activity and participation according to the LBP-CS.
  
  
  METHODS
  A cross-sectional repeated-measures questionnaire study was undertaken with thirty-one medically stable adults with CLBP who presented for treatment at two public Australian hospitals. Participants completed the LBP-CS Self-Report Checklist (LBP-CS-SRC) on two occasions (mean = 12.5 (SD = 4.5) days between administrations). The LBP-CS-SRC permits patients to self-rate their functioning according to the LBP-CS activity and participation categories and enables the derivation of activity limitation and participation restriction scales.
  
  
  RESULTS
  Patient ratings of individual LBP-CS categories generally exhibited good - excellent test-retest agreement (percentage exact agreement: 74.19-100.00%) and reliability (kappa: 0.53-1.00). The test-retest reliability coefficients of the LBP-CS-SRC activity (ICC = 0.94) and participation (ICC = 0.90) scales were excellent. The minimum detectable change values for the activity and participation scales were 8.11 and 15.26, respectively.
  
  
  CONCLUSIONS
  This study is the first to demonstrate that patients can provide reliable ratings of functioning using the LBP-CS. The LBP-CS-SRC was shown to be acceptably reliable and precise to support understanding of patients' perspectives on disability in rehabilitation practice and research.
authors.affiliation: Interdisciplinary Persistent Pain Centre, Gold Coast Hospital and Health Service, Gold Coast, Queensland, Australia; Occupational Therapy Department and the Orthopaedic Physiotherapy Screening Clinic, Royal Brisbane and Women's Hospital, Brisbane, Australia; Occupational Therapy, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Queensland, Australia. Electronic address: Karl.Bagraith@gmail.com.
authors.forename: Karl S
authors.initials: KS
authors.lastname: Bagraith
authors.affiliation: Occupational Therapy, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Jenny
authors.initials: J
authors.lastname: Strong
authors.affiliation: Occupational Therapy, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Meredith
authors.affiliation: Centre for Functioning and Health Research, Metro South Hospital and Health Service, Brisbane, Australia; Institute of Health and Biomedical Innovation and School of Public Health & Social Work, Queensland University of Technology, Brisbane, Australia.
authors.forename: Steven M
authors.initials: SM
authors.lastname: McPhail
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D001315:Australia; D057189:Checklist; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D006233:Persons with Disabilities; D005260:Female; D006801:Humans; D064702:International Classification of Functioning, Disability and Health; D017116:Low Back Pain / Q000150:complications*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D057566:Self Report; D011795:Surveys and Questionnaires
keywords: Agreement; Core sets; International Classification of Functioning, Disability and Health; Low back pain; Reliability