Validation of the Visual Analog Scale in Perennial Allergic and Non-Allergic Rhinitis: Association With Symptom Severity and Quality of Life

Abstract

Background: Although the visual analog scale (VAS) is recommended in guidelines for assessing perennial allergic rhinitis (PAR), its validity in non-allergic rhinitis (NAR) remains unclear. Objective: To evaluate the concurrent validity of the VAS in assessing symptom severity and its association with quality of life (QoL) outcomes in PAR and NAR. Methods: This cross-sectional study prospectively included adults with moderate to severe PAR and NAR, all of whom had experienced symptoms for more than 6 months and underwent skin prick and/or specific IgE testing. Individual nasal symptoms, total nasal symptom score (TNSS), VAS, and Rhinoconjunctivitis Quality of Life-36 (RCQ-36) scores were compared between groups. We assessed VAS validity via Spearman's correlation with TNSS. Participants were dichotomized at the median VAS to examine associations with RCQ-36 and symptom profiles. Results: Among 445 patients (298 PAR and 147 NAR), TNSS was lower in NAR, but VAS global scores and RCQ-36 domains were similar, except for a trend toward higher eye symptom burden in PAR. The VAS correlated moderately with TNSS in PAR (Spearman correlation = 0.49, 95% CI, 0.40-0.57) but weakly in NAR (Spearman correlation = 0.35; 95% CI, 0.20-0.49). Patients with a VAS result of 70 mm or greater (median cutoff) had significantly worse RCQ-36 in both groups, along with higher VAS for eye itching, postnasal drip, nasal voice, facial pressure, hyposmia, and cough. Greater nasal obstruction and rhinorrhea severity strongly correlated with poorer QoL. Conclusions: The VAS demonstrates comparable validity in PAR and NAR, effectively categorizing disease severity and QoL impairment. Nasal congestion and rhinorrhea severity are key drivers of reduced QoL in both conditions.