Self-reported disability according to the International Classification of Functioning, Disability and Health Low Back Pain Core Set: Test-retest agreement and reliability

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. (C) 2017 Elsevier Inc. All rights reserved.