Abstract
The nasal obstruction symptom evaluation (NOSE) scale is a validated disease-specific, self-completed questionnaire for the assessment of quality of life related to nasal obstruction. The aim of this study was to validate the Dutch (NL-NOSE) questionnaire. A prospective instrument validation study was performed in a tertiary academic referral center. Guidelines for the cross-cultural adaptation process from the original English language scale into a Dutch language version were followed. Patients undergoing functional septoplasty or septorhinoplasty and asymptomatic controls completed the questionnaire both before and 3 months after surgery to test reliability and validity. Additionally, we explored the possibility to reduce the NOSE scale even further using graded response models. 129 patients and 50 controls were included. Internal consistency (Cronbach's alpha 0.82) and test-retest reliability (intraclass correlation coefficient 0.89) were good. The instrument showed excellent between-group discrimination (Mann-Whitney U = 85, p < 0.001) and high response sensitivity to change (Wilcoxon rank p < 0.001). The NL-NOSE correlated well with the score on a visual analog scale measuring the subjective sensation of nasal obstruction, with exception of item 4 (trouble sleeping). Item 4 provided the least information to the total scale and item 3 (trouble breathing through nose) the most, particularly in the postoperative group. The Dutch version of the NOSE (NL-NOSE) demonstrated satisfactory reliability and validity. We recommend the use of the NL-NOSE as a validated instrument to measure subjective severity of nasal obstruction in Dutch adult patients.