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.