Patient-reported outcome questionnaires
The impact of COVID-19 on sinonasal symptoms was evaluated through the French version of the sino-nasal outcome test-22 (SNOT-22),9 a validated patient-reported outcome questionnaire from the original U.S. 20-item version.10
The impact of olfactory dysfunction on quality of life was assessed through the short version of the Questionnaire of Olfactory Disorders-Negative Statements (sQOD-NS).11 sQOD-NS is a 7-item patient-reported outcome questionnaire. Patients rated the item proposition from 0 (agree) to 3 (disagree) with total score ranging from 0 (significant impact of olfactory dysfunction on QoL) to 21 (no impact on QoL). Authors used sQOD-NS for its ease of completion.
The olfactory and gustatory questions were based on the smell and taste component of the National Health and Nutrition Examination Survey (NHNES).12 NHNES is a population survey that continuously monitors the health of adult citizens in the U.S. through a nationally representative sample of 5,000 persons on a yearly basis.12 The questions have been selected to characterize the variation, timing and associated-symptoms of both olfactory and gustatory dysfunction.
Psychophysical Olfactory Evaluation
The psychophysical olfactory evaluations were performed using the identification sniffin’ sticks test (Medisense, Groningen, The Netherlands), which is a validated objective test of olfactory dysfunction.13 A total of 16 scents were presented via a pen device to patients for 3 seconds followed by a forced choice from 4 given options with a total possible score of 16 points. According to the results, patients were classified as normosmic (score between 12-16), hyposmic (score between 9-11) or anosmic (score 8 or below).