RESUMO
OBJECTIVE: Translate, adapt, and validate the Anterior Skull Base Nasal Inventory 12 questionnaire (ASK Nasal-12) to Brazilian Portuguese. METHODS: A prospective longitudinal observational study was developed at the Skull Base Surgery Center clinic of the Irmandade Santa Casa de Misericórdia de São Paulo. There were five stages to translating the original ASK-12 questionnaire: two independent translations, consensus between the two, back-translation, comparison, and revision for the semi-final version. Internal consistency, reliability, and validation with a previous already validate questionnaire were all assessed. RESULTS: Over 30 months 72 patients in total were included in the study, of which six had to be excluded afterwards according to the research criteria. The internal consistency using Cronbach's Alpha was calculated and successful. Next the reliability and agreement between the test and retest were analyzed. The Minimally Important Clinical Difference (MCID) was calculated for the 13 scores at each of the four time points. Finally, the final translated version was validated with the SNOT-22 questionnaire. CONCLUSION: The translation, adaptation, and validation of the ASK Nasal-12 questionnaire into Brazilian Portuguese appear consistent and effective regarding its cultural equivalence for monitoring the QOL of patients undergoing transnasal access for endoscopic anterior skull base surgeries. LEVEL OF EVIDENCE: II.