A scoping review of Rasch analysis and item response theory in otolaryngology: Implications and future possibilities.

Objective: Item response theory (IRT) is a methodological approach to studying the psychometric performance of outcome measures. This study aims to determine and summarize the use of IRT in otolaryngological scientific literature. Methods: A systematic search of the Medline, Embase, and the Cochrane Library databases was performed for original English-language published studies indexed up to January 28, 2023, per the following search strategy: ("item response theory" OR "irt" OR "rasch" OR "latent trait theory" OR "modern mental test theory") AND ("ent" OR "otorhinolaryngology" OR "ear" OR "nose" OR "throat" OR "otology" OR "audiology" OR "rhinology" OR "laryngology" OR "neurotology" OR "facial plastic surgery"). Results: Fifty-five studies were included in this review. IRT was used across all subspecialties in otolaryngology, and most studies utilizing IRT methodology were published within the last decade. Most studies analyzed polytomous response data, and the most commonly used IRT models were the partial credit and the rating scale model. There was considerable heterogeneity in reporting the main assumptions and results of IRT. Conclusion: IRT is increasingly being used in the otolaryngological scientific literature. In the otolaryngology literature, IRT is most frequently used in the study of patient-reported outcome measures and many different IRT-based methods have been used. Future IRT-based outcome studies, using standardized reporting guidelines, might improve otolaryngology-outcome research sustainably by improving response rates and reducing patient response burden. Level of evidence: 2.