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

BACKGROUND AND OBJECTIVE: Diagnostic criteria of chronic rhinosinusitis with nasal polyps (CRSwNP) include, among others, olfactory dysfunction (OD). We hypothesize that patients suffering with CRSwNP are good at self-assessing their sense of smell through visual analogue scale (VAS) compared to smell tests.

METHODS: A controlled cross-sectional study was planned. Adults diagnosed with severe CRSwNP waiting for endoscopic sinus surgery were included. A cohort of healthy controls was also studied. All participants performed Barcelona smell test (BAST-24), sinonasal outcomes test 22 (SNOT-22), and VAS for loss of smell. CRSwNP underwent blood test (eosinophils count, total serum IgE), CT scan (Lund-Mackay Score), and nasal endoscopy.

RESULTS: 138 severe CRSwNP and 40 controls subjects were included. The BAST-24 identification score was strongly correlated with the VAS score in the CRSwNP group (rho=-0.79, p<0.001) but not in the control group (rho=-0.14; p=0.39), this difference between groups being statistically significant (p<0.001). A significant correlation of SNOT-22 item 21 (loss of smell) was also found with BAST-24 identification (rho=-0.65, p<0.001), this difference being statistically significant (Z=-2.43; p=0.015). In the ROC curve, the area under the curve (AUC) 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 OD in severe CRSwNP in daily clinical practice.