RESUMEN
BACKGROUND: The Shoulder Disability Questionnaire (SDQ) is a validated shoulder functional scale that has not yet been translated into Spanish. OBJECTIVE: The objective of this study was to develop and test the consistency of a Spanish translation of The Netherlands version of the SDQ (NSDQ). METHODS: A backtranslation process was used to generate a Spanish version of the NSDQ, called the S-SDQ. Subsequently, both the NSDQ and S-SDQ were administered to 30 bilingual (English/Spanish) subjects. Finally, the S-SDQ was administered to 35 monolingual Spanish-speaking subjects with shoulder pain on 2 occasions. External consistency between NSDQ and S-SDQ scores in the bilingual subjects, and between scores for the 2 S-SDQ applications in the monolingual subjects was assessed using the intraclass correlation coefficient (Ri). Internal consistency of the S-SDQ was assessed with Cronbach's alpha coefficient. RESULTS: In the bilingual subjects, the Ri between the NSDQ and S-SDQ scores was 0.991 (95% confidence interval [CI], 0.981-0.995). In the monolingual Spanish-speaking patients with shoulder pain, the Ri between the 2 S-SDQ scores was 0.99 (95% CI, 0.997-0.999). The Cronbach's alpha coefficient for the S-SDQ was 0.99. CONCLUSIONS: A highly consistent Spanish version of the NSDQ, the S-SDQ, was developed. This can be confidently used in clinical care and research settings for measurement of the functional status of shoulder joint disorders in Spanish-speaking subjects.
