Cross-Cultural Adaptation of a Health-Related Quality-of-Life Questionnaire for Children with Obstructive Sleep Disorders: Spanish Version of the OSD-6

Background/Objectives: To translate the OSD-6 questionnaire (6-item quality of life questionnaire for children with obstructive sleep disorders) into Spanish and to assess its psychometric properties and clinical usefulness. Methods: We included children with obstructive sleep apnea (OSA). All underwent polysomnography before and after adenotonsillectomy. Study variables included age, sex, symptoms, polysomnography values, body measurements, and Mallampati and Brodsky classification. Parents or caregivers completed the OSD-6 at baseline and 3 to 6 months after adenotonsillectomy. Following translation and back-translation of the instrument, we evaluated its internal consistency, reliability, construct validity, concurrent validity, predictive validity, and sensitivity to change. Results: We included 45 boys and 15 girls. Mean body mass index was 18 (standard deviation [SD] 4) kg/m2 and mean neck circumference was 28 (SD 5) cm. Seven per cent of children had Brodsky grade 0, 12% had grade 1, 27% had grade 2, 45% had grade 3, and 6% had grade 4. Mean apnea-hypopnea index (AHI) was 12 (SD 7) h−1 before adenotonsillectomy. The overall Cronbach’s alpha was 0.8. We found significant concurrent validity in each questionnaire domain and in the overall score. Predictive validity was significant for Mallampati scores (ANOVA p = 0.011) and borderline significant for AHI levels (ANOVA p = 0.069). The study demonstrated excellent sensitivity to change, both in terms of the overall analysis (p < 0.001) and in each domain (p < 0.001). Moreover, the test-retest reliability was found to be equally excellent (global intraclass correlation coefficient = 0.92 [0.89–0.95]). Conclusions: OSD-6 is a valid and reliable instrument to measure quality of life in children with OSA and can be used in Spanish-speaking countries.