Inter-observer reproducibility and responsiveness of a clinical severity scale in surgically treated carpal tunnel syndrome

OBJECTIVES: To test a recently proposed carpal tunnel syndrome (CTS) clinical severity scale for reproducibility between two observers (neurosurgeon and neurophysiologist) before surgery, for responsiveness to changes in clinical status 6 months after surgery, and for correlations with the electrophysiological findings and 'Boston Carpal Tunnel Syndrome Questionnaire' (BQ). MATERIAL AND METHODS: The tests were applied prospectively to a consecutive series of 254 hands with idiopathic CTS, referred for surgical decompression. The hands belonged to 219 subjects (177 women and 42 men, mean age 55.6). RESULTS: Percentage agreement between the two observers in assigning severity to the same class was 78% and Cohen coefficient kappa was 0.69 (P < 0.001). The scale was found to be responsive to changes in clinical status after surgery. Direct correlations were also found between the scale and patient age, duration of symptoms, BQ scores and the neurophysiological severity scale. The significance of these associations was maintained for 6 months after the operation. CONCLUSION: This clinical severity scale is simple, reproducible and sensitive for evaluating severity of CTS in patients undergoing surgery.