Diagnosing Carpal Tunnel Syndrome: Diagnostic Test Accuracy of Scales, Questionnaires, and Hand Symptom Diagrams-A Systematic Review.

Objective: To summarize and evaluate research on the accuracy of clinical diagnostic scales, questionnaires, and hand symptom diagrams/maps used for diagnosis of carpal tunnel syndrome (CTS).
Design: Systematic review of diagnostic test accuracy.
Literature Search: A comprehensive literature search of the MEDLINE, CINAHL, and Embase databases was conducted on January 20, 2020.
Study Selection Criteria: Studies that assessed at least 1 diagnostic accuracy property of the scales, questionnaires, and hand symptom diagrams used for the diagnosis of CTS.
Data Synthesis: The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed. Risk of bias and applicability concerns were assessed using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Diagnostic accuracy properties were summarized.
Results: Out of 4052 citations after removing duplicates, 21 articles met the inclusion criteria. Twelve articles reported on the diagnostic accuracy of scales and questionnaires, including the Bland questionnaire, Kamath and Stothard questionnaire, 6-item carpal tunnel syndrome symptoms scale (CTS-6), Boston Carpal Tunnel Questionnaire, Wainner clinical prediction rule, and Lo clinical prediction rule. Positive likelihood ratios ranged from 0.94 for the Boston Carpal Tunnel Questionnaire to 10.5 for the CTS-6, and negative likelihood ratios ranged from 1.04 to 0.05 for the same diagnostic tools, respectively. Nine studies reported the diagnostic accuracy of the Katz and Stirrat hand symptom diagram. Positive and negative likelihood ratios ranged from 1.42 to 8 and from 0.78 to 0.05, respectively. Only 4 studies had high methodologic quality.
Conclusion: Limited evidence supports high accuracy of the CTS-6, Kamath and Stothard questionnaire, and Katz and Stirrat hand symptom diagram. Other scales have lesser and more conflicting evidence. Further high-quality studies are necessary to examine the diagnostic accuracy of these tests to assist ruling in or ruling out CTS. J Orthop Sports Phys Ther 2020;50(11):622-631. Epub 16 Sep 2020. doi:10.2519/jospt.2020.9599 .