Validating the Adaptive Sinonasal Outcome Test (SNOT): A Clinically Reliable Tool for Chronic Rhinosinusitis Assessment

Highlight

• The adaptive Sinonasal Outcome Test (SNOT) was validated in a large patient cohort for internal consistency, reliability, and responsiveness.
• Adaptive SNOT scores correlated significantly with objective disease severity measured by Lund-Mackay CT scoring.
• The instrument demonstrated strong intrarater reliability and sensitivity to clinical changes post-treatment.
• Adaptive SNOT effectively captures chronic rhinosinusitis (CRS) and allergic rhinitis symptom burden along with related domains like sleep, psychological health, and productivity.

Study Background

Chronic rhinosinusitis (CRS) is a prevalent inflammatory disease affecting the sinonasal mucosa, leading to symptoms such as nasal congestion, facial pain, anosmia, and impaired quality of life. Globally, CRS significantly burdens health systems due to its chronicity, symptom complexity, and frequent need for medical and surgical interventions. Accurately assessing symptom severity and changes following therapy is pivotal for personalized patient care and clinical research.

Patient-reported outcome measures (PROMs) play a crucial role in capturing subjective disease impact. The Sino-Nasal Outcome Test (SNOT) is widely adopted internationally to evaluate CRS symptoms. However, conventional fixed-length SNOT instruments can be time-consuming and may not efficiently capture the full symptomatic landscape across diverse patient profiles.

Adaptive questionnaires—tailoring items dynamically based on previous responses—offer potential advantages of reduced respondent burden, precision, and adaptability. An adaptive version of the SNOT instrument was developed previously, exhibiting concordance with objective imaging findings. Nonetheless, comprehensive validation assessing psychometric properties including factor structure, internal consistency, convergent and discriminant validity, and responsiveness to clinical change was lacking.

Study Design

This diagnostic validation study prospectively recruited consecutive patients aged 15 years and older presenting for assessment of sinonasal symptoms across multiple centers between January 2024 and August 2025. Participants completed the adaptive SNOT instrument electronically, covering CRS and allergy-related symptoms as well as secondary domains such as ear symptoms, sleep disturbance, psychological distress, and productivity impairment.

Computed tomography (CT) sinus imaging was obtained in a sub-cohort of 70 patients for objective disease severity quantification using Lund-Mackay CT scores (LMCT). General health status was concurrently measured using the Patient-Reported Outcomes Measurement Information System (PROMIS).

Psychometric analyses included factor analysis to determine underlying domain structure, internal consistency via Cronbach’s alpha, intrarater reliability using Cohen’s kappa, Spearman correlation, and intraclass correlation coefficient (ICC). The ability of adaptive SNOT scores to discriminate between patients with different LMCT severity (less than 5 vs. 5 or greater) was assessed by mean differences and effect sizes (Cohen’s d). Responsiveness was evaluated by comparing scores before and after treatment interventions (medical or surgical) for CRS.

Key Findings

A total of 1072 patients were included, predominantly female (72.9%) with a mean age of 54 years (SD 21). Factor analysis supported the structural validity of the adaptive SNOT, confirming distinct symptomatic domains.

Internal consistency was robust, and domain-specific adaptive SNOT scores exhibited substantial intrarater reliability (Cohen kappa 0.72-0.75 across nasal and full domains), indicating stable repeatability of patient responses.

Importantly, patients with LMCT scores ≥5 had significantly higher adaptive SNOT nasal domain scores compared to those with LMCT <5 (difference in means, 0.33; 95% CI 0.03–0.63; Cohen d = 0.80), attesting to the instrument’s discriminant validity in reflecting objective disease severity. The all-domain adaptive SNOT score also differentiated these groups (difference in means, 3.04; 95% CI 0.02–6.05; Cohen d = 0.57).

Convergent validity was supported by correlations between adaptive SNOT scores and PROMIS measures of physical, mental, social, and global health domains, ranging from low to strong associations, reflecting the broad impact of CRS and allergic symptoms on quality of life.

Crucially, the adaptive SNOT nasal and overall domain scores were responsive to clinical improvement; patients receiving a CRS treatment intervention showed a meaningful reduction in scores from a mean 9.12 to 2.47 (95% CI 6.37–11.87 to 0.89–4.05) with a large effect size (Cohen d = 0.76), demonstrating sensitivity to change post-treatment.

Expert Commentary

This comprehensive validation of the adaptive SNOT establishes it as a reliable and valid PROM exhibiting psychometric rigor and clinical relevance in CRS management. By confirming an association with imaging severity and broad health impacts, the adaptive instrument supports nuanced patient assessment for both clinical care and research.

Compared to fixed-length PROMs, the adaptive SNOT may reduce patient burden while maintaining precision, enabling tailored symptom tracking across heterogeneous CRS populations and allergic rhinitis comorbidities. Given the chronic and multifactorial nature of CRS, capturing secondary domains such as sleep and psychological factors is essential, enhancing holistic patient-centered care.

Limitations include the modest sub-cohort size for CT validation and potential variability in treatment approaches that may influence responsiveness metrics. Further studies could explore longitudinal use, minimal clinically important differences, and cross-cultural validations.

Conclusion

The adaptive Sinonasal Outcome Test is a validated, psychometrically sound instrument for assessing sinonasal symptoms related to chronic rhinosinusitis and allergic rhinitis. It reliably corresponds with objective CT findings, measures multiple symptom domains comprehensively, and is responsive to clinical change. This supports its integration into routine clinical practice and prospective research trials to improve patient-centered assessment and treatment outcome evaluation.

Funding and Trial Registration

The study was supported by institutional research grants. There was no mention of a clinical trial registration number in the source publication.

References

1. Zhang SK, Gilani S, Stanlie A, et al. Validation of an Adaptive Sinonasal Outcome Test. JAMA Otolaryngol Head Neck Surg. 2026;152(7):659-668. doi:10.1001/jamaoto.2026.3337
2. Hopkins C, Gillett S, Slack R, Lund VJ, Browne JP. Psychometric validity of the 22-item Sinonasal Outcome Test. Clin Otolaryngol. 2009;34(5):447-454.
3. Lund VJ, Mackay IS. Staging in rhinosinusitus. Rhinology. 1993;31(4):183-184.