A brief version of the questionnaire of olfactory disorders in patients with chronic rhinosinusitis

Abstract

Background: The Questionnaire of Olfactory Disorders-Negative Statements (QOD-NS) is a valuable instrument in the measurement of olfactory-specific quality of life (QOL). In the clinical setting, patients can be overwhelmed with the time required to complete questionnaires. Our objective was to develop a brief version of the QOD-NS to streamline clinical care and research.

Methods: QOD-NS scores from 221 subjects were used to determine which subset of the 17 QOD-NS questions best correlated with total and subdomain QOD-NS scores. An initial pool of 11 questions was made by removing items with ρ < 0.80 to their respective subdomain scores. Next, 500 bootstrapped samples were taken. On each sampe, an all-subsets regression was performed with total QOD-NS scores and QOD-NS subdomain scores as the outcomes. From this, our "top" and "bottom" 10 subsets were identified based on mean r2 value, representation in bootstrap analysis, and number of items.

Results: All of our top subsets had excellent correlation with total and subdomain QOD-NS scores (mean r2 > 0.90). Our top choice has 7 total questions, is representative of all subdomains, has a mean r2 = 0.92, and was represented in 323 of our 500 bootstrapped samples. The worst-performing subset has 5 items, mean r2 = 0.81, and was represented in only 1 bootstrapped sample.

Conclusions: Using less than half of the questions in the QOD-NS, excellent correlations with both total and domain-specific scores are achieved. A brief version of the QOD-NS may prove useful in future clinical and research settings.

Keywords: olfaction; quality of life; questionnaire of olfactory disorders; sinusitis; smell.

© 2019 ARS-AAOA, LLC.

Figures

Figure 1:. Bubble Plot of QOD-NS Question Subsets

Each bubble represents a subset of QOD-NS questions. Bubble size represents the number of QOD-NS questions in the subset. Blue bubbles represent the “top ten” performing subsets, red bubbles represent the “bottom ten” performing subsets. This figure illustrates the top and bottom subsets determined through correlation with the original questionnaire and bootstrap samples.