Cross-cultural adaptation and validation of the Sinus and Nasal Quality of Life Survey (SN-5) into Brazilian Portuguese.

INTRODUCTION The concept of quality of life is subjective and variable definition, which depends on the individual's perception of their state of health. Quality of life questionnaires are instruments designed to measure quality of life, but most are developed in a language other than Portuguese. Questionnaires can identify the most important symptoms, focus on consultation, and assist in defining the goals of treatment. Some of these have been validated for the Portuguese language, but none in children. OBJECTIVE To validate the translation with cross-cultural adaptation and validation of the Sinus and Nasal Quality of Life Survey (SN-5) into Portuguese. METHODS Prospective study of children aged 2-12 years with sinonasal symptoms of over 30 days. The study comprised two stages: (I) translation and cross-cultural adaptation of the SN-5 into Portuguese (SN-5p); and (II) validation of the SN5-p. Statistical analysis was performed to assess internal consistency, test-retest reliability, and sensitivity, as well as construct and discriminant validity and standardization. RESULTS The SN-5 was translated and adapted into Portuguese (SN-5p) and the author of the original version approved the process. Validation was carried out by administration of the SN-5p to 51 pediatric patients with sinonasal complaints (mean age, 5.8±2.5 years; range, 2-12 years). The questionnaire exhibited adequate construct validity (0.62, p<0.01), internal consistency (Cronbach's alpha=0.73), and discriminant validity (p<0.01), as well as good test-retest reproducibility (Goodman-Kruskal gamma=0.957, p<0.001), good correlation with a visual analog scale (r=0.62, p<0.01), and sensitivity to change. CONCLUSION This study reports the successful translation and cross-cultural adaptation of the SN-5 instrument into Brazilian Portuguese. The translated version exhibited adequate psychometric properties for assessment of disease-specific quality of life in pediatric patients with sinonasal complaints.