[Spanish validation of the Boston Carpal Tunnel Questionnaire].

INTRODUCTION AND OBJECTIVE

To describe the process of cultural adaptation and validation of the Boston Carpal Tunnel Questionnaire (BCTQ) measuring symptom intensity, functional status and quality of life in carpal tunnel syndrome patients and to report the psychometric properties of this version.

MATERIAL AND METHODS

A 3 expert panel supervised the adaptation process. After translation, review and back-translation of the original instrument, a new Spanish version was obtained, which was administered to 2 patient samples: a pilot sample of 20 patients for assessing comprehension, and a 90 patient sample for assessing structural validity (factor analysis and reliability), construct validity and sensitivity to change. A re-test measurement was carried out in 21 patients. Follow-up was accomplished in 40 patients.

RESULTS

The questionnaire was well accepted by all participants. Celling effect was observed for 3 items. Reliability was very good, internal consistency: αS=0.91 y αF=0.87; test-retest stability: rS=0.939 and rF=0.986. Both subscales fitted to a general dimension. Subscales correlated with dynamometer measurements (rS=0.77 and rF=0.75) and showed to be related to abnormal 2-point discrimination, muscle atrophy and electromyography deterioration level. Scores properly correlated with other validated instruments: Douleur Neuropatique 4 questions and Brief Pain Inventory. BCTQ demonstrated to be sensitive to clinical changes, with large effect sizes (dS=-3.3 and dF=-1.9).

CONCLUSIONS

The Spanish version of the BCTQ shows good psychometric properties warranting its use in clinical settings.