Validation of Visual Analogue Scale for loss of smell as a quick test in chronic rhinosinusitis with nasal polyps

Abstract

Background and objectives: The diagnostic criteria of chronic rhinosinusitis with nasal polyps (CRSwNP) include olfactory dysfunction. We hypothesize that patients with CRSwNP can self-assess their sense of smell better using a visual analog scale (VAS) than using smell tests.

Methods: A controlled cross-sectional study was performed. Adults diagnosed with severe CRSwNP waiting for endoscopic sinus surgery were included. A cohort of healthy controls was also studied. All participants completed the Barcelona Smell Test 24 (BAST-24), the 22-item Sinonasal Outcomes Test 22 (SNOT-22), and a VAS for loss of smell. Patients with CRSwNP underwent blood testing (eosinophil count, total serum IgE), computed tomography (Lund-Mackay Score), and nasal endoscopy.

Results: The study population comprised 138 patients with severe CRSwNP and 40 controls. The BAST-24 identification score was strongly correlated with the VAS score in the CRSwNP group (p=-0.79, P<.001) but not in the control group (p=-0.14; P=.39), this difference between groups being statistically significant (P<.001). A significant correlation was found between SNOT-22 item 21 (loss of smell) and BAST-24 identification (p=-0.65, P<.001), this difference being statistically significant (Z=-2.43; P=.015). The area under the receiver operating curve was 0.85, with 72.5% sensitivity and 93.1% specificity.

Conclusion: This study demonstrates a potential role of the VAS score for the screening of olfactory dysfunction in severe CRSwNP in daily clinical practice.