Assessment of validity, reliability, responsiveness and bias of three commonly used patient-reported outcome measures in carpal tunnel syndrome.

BACKGROUND In recent years there has been an increase in the use of self-administered questionnaires to accurately assess intervention outcomes in hand surgery in order to determine the quality of healthcare. This prospective study aims to evaluate and assess the validity, reliability, responsiveness, and bias of a number of outcome measure for Carpal Tunnel Syndrome (CTS) including the disease-specific Boston questionnaires (BQ), and the region-specific Disability of Arm, Shoulder, and Hand (DASH) questionnaires and Manchester Modified Disabilities of the Arm, Shoulder and Hand (M(2)DASH) questionnaires, and comparing the results to Nerve Conduction Studies (NCS). MATERIALS AND METHODS Forty-eight patients with clinical signs of CTS confirmed by NCS completed the BQ, DASH and M(2)DASH questionnaire at different time intervals peri-operatively. The scores were analysed to assess validity, reliability, responsiveness, and bias of the questionnaires. Validity analysis for the three questionnaires showed strong positive correlations and there was no age, gender, hand dominance, or side affected bias in the questionnaires. RESULTS No significant correlation was obtained between the questionnaires and NCS. Significant results for responsiveness were noted in BQ symptom severity scale only. CONCLUSION 1. This study ha show n that the BQ, DASH and M(2)DASH questionnaires are valid and reliable outcome measures for CTS. 2. In terms of responsiveness, the DASH and M(2)DASH questionnaires are not as responsive as the BQ scores over the initial post-operative recovery period. 3. We would therefore recommend that the Boston Questionnaire be used to assess early post-operative patient related outcome measures for Carpal Tunnel Syndrome.