The Reliability of the CTS-6 for Examiners With Varying Levels of Clinical Experience

Abstract

Purpose: To assess the interrater reliability of the CTS-6 for examiners with varying levels of clinical expertise. We also aimed to analyze this instrument's sensitivity (Sn) and specificity (Sp), using the CTS-6 score obtained by a hand surgeon as a reference standard.

Methods: Three examining groups consisting of medical students, occupational hand therapists, and hand surgeons examined a consecutive series of patients in an academic upper-extremity clinic. A total of 3 examiners (1 from each group) recorded a CTS-6 score for each patient. The examiners were blinded to the scores from the other groups. The interrater reliability was determined between the groups with respect to the diagnosis of CTS and the individual CTS-6 components. Sn and Sp were calculated for each of the groups using the CTS-6 obtained by the hand surgeons as the reference standard.

Results: Two hundred seven patients were included. For the diagnosis of CTS (CTS-6 score of 12 or greater as determined by a hand surgeon), there was substantial agreement between the 3 groups (Fleiss kappa 0.73; 95% CI [0.65 -0.82]; P < .05). For individual CTS-6 components, the agreement between the groups was highest for assessing subjective numbness and lowest for assessing a Tinel sign (Fleiss kappa of 0.77 and 0.49, respectively). The Sn/Sp for diagnosing CTS was 87%/91% for the medical student group and 81%/95% for the occupational hand therapist group.

Conclusions: The CTS-6 can be reliably used as a screening and diagnostic tool for CTS by clinicians with a variety of experience levels and without specific fellowship training in upper-extremity surgery.

Type of study/level of evidence: Diagnostic I.

Keywords: CTS-6; Carpal tunnel syndrome; hand surgery; hand therapy; interrater reliability; medical education.