Predictors of olfactory dysfunction in patients with chronic rhinosinusitis

Objectives: To measure the prevalence of and identify clinical characteristics associated with poor olfactory function in a large cohort of patients with chronic rhinosinusitis (CRS). Study Design: Multi-institutional, cross sectional analysis. Methods: An objective measure of olfactory dysfunction, the Smell Identification Test, demographic data, clinical factors, and comorbidity data were collected from a cohort of 367 patients who presented with CRS at three tertiary care centers. Data were analyzed using univariate and multivariate analyses. Results: Sixty-four percent of men and women aged 18 to 64 had olfactory dysfunction whereas 95% of patients older than or equal to 65 years had olfactory dysfunction (P < .001); no significant difference was noted by gender. By multivariate logistic regression analysis, patients with nasal polyposis [Odds ratio (OR) 2.4, 95% confidence interval (CI) 1.3-4.2, P=.003] and patients older than or equal to 65 years (OR 10.0, 95% CI 2.3-43.7, P=.002) were at increased risk of hyposmia. Patients with nasal polyposis (OR 13.2, 95% CI 5.7-30.7, P < .001), asthma (OR 4.2, 95% CI 1.8-9.8, P=.001), older than or equal to 65 years (OR 15.6, 95% CI 2.3-104.9, P=.005), and smokers (OR 7.6, 95% CI 1.8-31.6, P=.005) were at increased risk of anosmia. Conclusions: Poor olfactory function is common in patients with CRS. Age, nasal polyposis, smoking, and asthma were significantly associated with olfactory dysfunction in patients with CRS. Neither prior endoscopic sinus surgery nor a history of allergic rhinitis was associated with olfactory dysfunction. Septal deviation and inferior turbinate hypertrophy were associated with normal olfactory function.