Psychometric properties of chronic low back pain diagnostic classification systems: a systematic review.

Objectives: To identify and critically appraise studies evaluating psychometric properties of functionally oriented diagnostic classification systems for Non-Specific Chronic Low Back Pain (NS-CLBP).

Methods: This review employed methodology consistent with PRISMA guidelines. Electronic databases and journals: (PubMed, EMBASE, Cochrane, PEDro, CINAHL, Index to chiropractic literature, ProQuest, Physical Therapy, Journal of Physiotherapy, Canadian Physiotherapy and Physiotherapy Theory and Practice) were searched from inception until January 2020. Included studies evaluated the validity and reliability of NS-CLBP diagnostic classification systems in adults. Risk of bias was assessed using a Critical Appraisal Tool.

Results: Twenty-two studies were eligible: Five investigated inter-rater reliability, and 17 studies analyzed validity of O'Sullivan's classification system (OCS, n = 15), motor control impairment (MCI) test battery (n = 1), and Pain Behavior Assessment (PBA, n = 1). Evidence from multiple low risk of bias studies demonstrates that OCS has moderate to excellent inter-rater reliability (kappa > 0.4). Also, two low risk of bias studies support of OCS-MCI subcategory. Three tests within the MCI test battery show acceptable inter- and intra-rater reliability for clinical use (the "sitting knee extension," the "one leg stance," and the "pelvic tilt" tests). Evidence for the reliability and validity of the PBA is limited to one high bias risk study.

Conclusions: Multiple low risk of bias studies demonstrate strong inter-rater reliability for OCS classification specifically OCS-MCI subcategory. Future studies with low risk of bias are needed to evaluate reliability and validity of the MCI test battery and the PBA.