Validation of a novel allergy‐specific domain for the 22‐item sino‐nasal outcomes test

Abstract

AbstractObjectivesTo develop and assess the validity of a novel allergy‐specific domain for the 22‐item sino‐nasal outcomes test (SNOT‐22), to provide a new tool that efficiently quantifies the impact of allergic rhinitis (AR) concurrent with chronic rhinosinusitis.Study DesignProspective validation study.SettingTertiary care hospital and community‐based clinic.MethodsProposed items were developed based on clinician and patient input, and further assessed via factor analysis and for internal consistency (n = 1987). Items were then additionally assessed for convergent and discriminant validity (n = 415), applying data from concurrent completions of the Nasal Obstruction and Septoplasty Effectiveness Scale (NOSE), Mini‐Rhinoconjunctivitis Quality‐of‐Life Questionnaire (MiniRQLQ), and validated global health assessments. Assessments of intra‐rater reliability, responsiveness to change, and qualitative input were also performed.ResultsFactor analysis demonstrated that proposed allergy items mapped to a single domain. Items were internally consistent (Cronbach α: 0.80 within domain, 0.91 within all SNOT). In assessments of convergent validity, domain scores were associated with MiniRQLQ (Spearman's ρ: 0.46, 95% confidence interval [CI]: 0.30‐0.59) and NOSE scores (0.36, 95% CI: 0.27‐0.44). The novel items also discriminated among clinical states: a 1‐point increase in domain score was associated with an 8.32 (95% CI: 5.43‐12.75) increase in the odds of prompting a visit for allergy‐related symptoms and a 1.52 (95% CI: 1.13‐2.05) increase in the odds of positive allergy testing. Intra‐rater reliability was substantial (Cohen's κ: 0.8, 95% CI: 0.8‐0.9), and responsiveness to change was demonstrated (mean difference: −0.6, 95% CI: −0.8 to −0.4).ConclusionsThis novel domain is a valid, efficient measure of AR alongside rhinosinusitis.