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. 2022 Feb;12(2):191-199.
doi: 10.1002/alr.22878. Epub 2021 Aug 26.

Exploring possibilities for shortening the 22-item Sino-Nasal Outcome Test (SNOT-22) using item response theory

David T Liu  1 , Katie M Phillips  2 , Marlene M Speth  3 , Gerold Besser  1 , Christian A Mueller  1 , Ahmad R Sedaghat  2
Affiliations

Exploring possibilities for shortening the 22-item Sino-Nasal Outcome Test (SNOT-22) using item response theory

David T Liu et al. Int Forum Allergy Rhinol. 2022 Feb.

Abstract

Background: Even with a high-quality instrument, such as the 22-item Sino-Nasal Outcome Test (SNOT-22), patients can be overwhelmed by repeated completion of questionnaires, leading to nonadherence and reduced data quality. The aim of this study was to evaluate whether the SNOT-22 could be made more concise without losing the valuable information that it provides.

Methods: A modern psychometric approach, item response theory (IRT), was used on a sample of 800 patients with chronic rhinosinusitis (CRS). The SNOT-22 was refined based on: (1) the item information criteria, retaining only items with above-average information; and (2) the total test information, retaining only the most discriminating items to cover at least 30% of the information within each subdomain. The preliminary validity and reliability of these refined scales were assessed using Cronbach's alpha and Pearson's correlation.

Results: Using an IRT approach, we find that it may be possible to shorten the SNOT-22 to an 11-item and six-item version based on psychometric properties. Item information functions of the shortened 11-item and six-item scales demonstrate that both versions accurately covered the CRS symptom-severity continuum. Preliminary reliability and validity analysis showed that both refined scales had good to excellent reliability (Cronbach's alpha ≥ 0.80) and were highly associated with the original full-length scale (r ≥ 0.90).

Conclusion: IRT provides data-driven opportunities for the continuous development and refinement of the SNOT-22. While patient and provider input must be accounted for too, our results show that future revisions of the SNOT-22 could include significantly fewer items.

Keywords: CRS; IRT; SNOT-22; chronic rhinosinusitis; item response theory; quality of life.

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References

REFERENCES

    1. Fokkens WJ, Lund VJ, Hopkins C, et al. European Position Paper on rhinosinusitis and nasal polyps 2020. Rhinology. 2020;58(Suppl S29):1-464.
    1. Orlandi RR, Kingdom TT, Smith TL, et al. International consensus statement on allergy and rhinology: rhinosinusitis 2021. Int Forum Allergy Rhinol. 2021;11(3):213-739.
    1. Rosenfeld RM, Piccirillo JF, Chandrasekhar SS, et al. Clinical practice guideline (update): adult sinusitis. Otolaryngol Head Neck Surg. 2015;152(Suppl 2):S1-S39.
    1. Speth MM, Hoehle LP, Phillips KM, Caradonna DS, Gray ST, Sedaghat AR. Changes in chronic rhinosinusitis symptoms differentially associate with improvement in general health-related quality of life. Ann Allergy Asthma Immunol. 2018;121(2):195-199.
    1. Campbell AP, Phillips KM, Hoehle LP, et al. Depression symptoms and lost productivity in chronic rhinosinusitis. Ann Allergy Asthma Immunol. 2017;118(3):286-289.

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