Development and psychometric validation of the Chronic Rhinosinusitis Control Test

Disease control assessment for chronic rhinosinusitis (CRS) remains a challenge. In this study, we develop and psychometrically validate a new patient-reported outcome measure, the Chronic Rhinosinusitis Control Test (CRCT), for assessing CRS control.

The CRCT, which includes 8 items and has a score that ranges from 0-31, incorporates the perspectives of key stakeholders (patients and healthcare providers) and was developed incorporating methodologic guidance from the COSMIN initiative and United States Food and Drug Administration. Psychometric validation was performed in line with recommendations from the COSMIN initiative to establish validity, reliability and responsiveness in a sample of 545 CRS patients and with the participation of 23 expert rhinologists.

The CRCT has excellent face validity, content validity, concurrent validity, internal consistency, test-retest reliability, and responsiveness. Factor analysis reveals that the CRCT has 2 subdomains: sinonasal and impairment subdomains in addition to a final item related to CRS-related oral corticosteroid usage in the past 3 months. Using a distribution-based and multiple anchorbased methods, the CRCT has a minimal clinically important difference (MCID) of 4 points. After 23 expert rhinologists independently classified all possible combinations of scoring on the CRCT, scores of ≤7 indicate controlled CRS, 8 to 15 (inclusive) partly controlled CRS and ≥16 uncontrolled CRS.

The CRCT is a psychometrically validated measure of CRS control. CRS may be classified as controlled based on CRCT score ≤7, partly controlled with CRCT score of 8 to 15 (inclusive) and uncontrolled with CRCT score ≥16. The MCIDs for improvement and worsening are both 4.