Patient‐Reported Outcome Measures for Severe Recurrent Bilateral Nasal Polyps: Psychometric Evaluation and Content Validity

Objective To date, no patient‐reported outcome measures have been specifically developed to assess pharmacological treatment effect in participants with severe chronic rhinosinusitis (CRS) with recurrent bilateral nasal polyps (NP). These studies aimed to assess (1) the psychometric properties and (2) content validity of Visual Analogue Scales (VAS) assessing NP symptom severity. Study Design (1) Retrospective psychometric validation study using clinical trial data and (2) cross‐sectional qualitative patient interview study. Setting (1) Multicentre trial; (2) real‐world. Methods (1) Psychometric validation was performed using data from a randomized, double‐blind, placebo‐controlled, Phase II study (NCT01362244) investigating the effect of mepolizumab in 105 participants with severe, recurrent bilateral NP currently needing polypectomy surgery. (2) Content validity was explored through cognitive debriefing interviews in 27 adults with severe CRS with recurrent bilateral NP who had received NP surgery in the past 10 years (NCT03221192). Results (1) Acceptable reliability, validity, and responsiveness were shown for individual VAS items, although the loss of smell VAS item performed poorly in several analyses, suggesting further evaluation of this item is needed. (2) All individual VAS items were well understood, considered relevant and were consistently interpreted by most participants, providing evidence for their content validity. Conclusion These findings support the use of symptom VAS measures to evaluate disease experience and treatment effect in clinical trials of participants with severe CRS with recurrent bilateral NP.