Criterion-concurrent validity of spinal mobility tests in ankylosing spondylitis: a systematic review of the literature.

Objective: To examine the level of evidence for criterion-concurrent validity of spinal mobility assessments in patients with ankylosing spondylitis (AS).

Methods: Guidelines proposed in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were used to undertake a search strategy involving 3 sets of keywords: accura*, truth, valid*; ankylosing spondylitis, spondyloarthritis, spondyloarthropathy, spondylarthritis; mobility, spinal measure*, (a further 16 keywords with similar meaning were used). Seven databases were searched from their inception to February 2014: AMED, Embase, ProQuest, PubMed, Science Direct, Scopus, and Web of Science. The Quality Assessment of Diagnostic Accuracy Studies (with modifications) was used to assess the quality of articles reviewed. An article was considered high quality when it received "yes" in at least 9 of the 13 items.

Results: From the 741 records initially identified, 10 articles were retained for our systematic review. Only 1 article was classified as high quality, and this article suggests that 3 variants of the Schober test (original, modified, and modified-modified) poorly reflect lumbar range of motion where radiographs were used as the reference standard.

Conclusion: The level of evidence considering criterion-concurrent validity of clinical tests used to assess spinal mobility in patients with AS is low. Clinicians should be aware that current practice when measuring spinal mobility in AS may not accurately reflect true spinal mobility.