Comparison of responsiveness of the Japanese Society for Surgery of the Hand version of the carpal tunnel syndrome instrument to surgical treatment with DASH, SF-36, and physical findings

BACKGROUND The Japanese Society for Surgery of -the Hand version of the Carpal Tunnel Syndrome Instrument (CTSI-JSSH), which consists of two parts--one for symptom severity (CTSI-SS) and the other for functional status (CTSI-FS)--is a self-administered questionnaire specifically designed for carpal tunnel syndrome. The responsiveness of the CTSI-JSSH was compared with that of the JSSH version of the Disability of Arm, Shoulder, and Hand questionnaire (DASH), the official Japanese version of the 36-Item Short Form Health Survey (SF-36, version 1.2), and physical examinations to elucidate the role of the CTSI-JSSH for evaluating patients with carpal tunnel syndrome. METHODS Preoperatively, a series of 60 patients with carpal tunnel syndrome completed the CTSI-JSSH, DASH, and SF-36. Results of physical examinations, including grip strength, pulp pinch, and static two-point discrimination of the thumb, index, and long fingers, were recorded. Three months after carpal tunnel release surgery the patients were asked to fill out the same questionnaires, and the physical examinations were repeated. The responsiveness of all the instruments was examined by calculating the standardized response mean (SRM) and effect size (ES). Correlation coefficients were calculated between questionnaire change scores and patient satisfaction scores as well as between the CTSI change scores and those of the DASH and SF-36. RESULTS The largest responsiveness was observed in the CTSI-SS (SRM/ES: -1.00/-1.08) followed by the CTSI-FS (-0.76/-0.63), and bodily pain subscale of SF-36 (SF-36-BP, 0.45/0.55), and the DASH (-0.46/-0.47). Only the change scores of the CTSI-SS had significant correlation with patient satisfaction (r = 0.34, P < 0.01). An absolute value of Spearman's correlation coefficient of >0.5 was observed between the change scores of the CTSI-SS and the DASH, the CTSI-SS and the SF-36-BP, the CTSI-FS and the DASH, and the DASH and the SF-36-BP. CONCLUSION The CTSI-JSSH was proven to be more sensitive to clinical changes after carpal tunnel release than the other outcome measures and should be used to evaluate patients with carpal tunnel syndrome who speak Japanese as their native language.