Validation of an Adaptive Sinonasal Outcome Test.

Importance: The Sino-Nasal Outcome Test (SNOT) is used worldwide to assess chronic rhinosinusitis (CRS). An adaptive form of this instrument has established concordance between subjective patient-reported outcomes and objective imaging findings, but its broader psychometric properties have yet to be evaluated. Objective: To evaluate whether the adaptive SNOT can function as a validated instrument. Design, Setting, and Participants: This validation diagnostic study of internal consistency, reliability, responsiveness, and convergent and discriminant validity of an adaptive SNOT instrument included consecutive patients 15 years and older who prospectively completed the adaptive SNOT, including factor analysis on 1072 responses. Computed tomography (CT) imaging of the sinuses was performed in 70 patients. Data were collected from January 2024 to August 2025, and data were analyzed from August to September 2025. Exposures: CRS and allergy-related symptoms as well as secondary ear, sleep, psychological, and productivity domains were assessed through completion of the adaptive SNOT instrument. Lund-Mackay CT scores (LMCT) were calculated to measure objective disease severity in sinus imaging, while Patient-Reported Outcomes Measurement Information System scores were used to assess general health. Main Outcomes and Measures: Factor analysis and internal consistency were assessed. Adaptive SNOT scores in patients with LMCT scores less than 5 or 5 and greater were evaluated via differences in means and effect sizes. Convergent validity was evaluated with Spearman ρ. Intrarater reliability was evaluated with Cohen κ, Spearman ρ, and intraclass correlation coefficient. Results: Of 1072 included patients, 782 (72.9%) were female, and the mean (SD) age was 54 (21) years. The adaptive SNOT nasal domain and all-domain scores clearly distinguished between patients with LMCT scores of 5 and greater and those with LMCT scores less than 5 (nasal domain score: difference in means, 0.33; 95% CI, 0.03-0.63; Cohen d = 0.80; all-domain score: difference in means, 3.04; 95% CI, 0.02-6.05; Cohen d = 0.57). Adaptive SNOT scores also demonstrated associations with physical, mental, social, and global health (associations ranged from low to strong). Intrarater reliability was substantial for both the nasal domain alone (Cohen κ range, 0.72-0.74) and across all domains (Cohen κ range, 0.73-0.75). Additionally, the adaptive SNOT nasal and all-domain scores were responsive to change and improved among patients who received CRS treatment with medication or surgery from a mean score of 9.12 (95% CI, 6.37-11.87) to 2.47 (95% CI, 0.89-4.05) (Cohen d = 0.76). Conclusions and Relevance: Findings of this validation diagnostic study support the validation of the adaptive SNOT instrument for assessing CRS-related and allergic rhinitis-related symptoms in clinical and research settings.