Development and Preliminary Validation of a New Patient-Reported Outcome Measure for Chronic Rhinosinusitis (CRS-PRO)

Abstract

Patient-reported outcome (PRO) measures developed and validated on patients with the currently defined phenotypes of chronic rhinosinusitis (CRS) are needed to support clinical trials in CRS. This study developed and examined the initial reliability and validity of the CRS-PRO, a new PRO measure of CRS. Instrument development was performed through structured interviews and focus groups with clinical experts and 45 patients with CRS meeting current definitions of disease, 21 patients with CRS without nasal polyps (CRSsNP), and 24 patients with CRS with nasal polyps (CRSwNP) to identify items important to patients. Then another 50 patients (32 with CRSsNP and 18 with CRSwNP) with stable CRS symptoms were enrolled to evaluate the reliability of the instrument. Each patient completed the CRS-PRO, Sinonasal Outcome Test-22 (SNOT-22), and 4 Patient-Reported Outcome Measurement Information System short forms at the baseline visit and then at least 7 days later. After the development process, 21 items were identified from the conceptual domains of physical symptoms, sensory impairment, psychosocial effects, and life impact. Using the responses of the 50 patients with CRS, 21 draft items were further refined to 12 items by eliminating conceptually similar or highly correlated items or those with low mean symptom severity. The 12-item questionnaire was shown to have excellent internal consistency (Cronbach α, 0.86) and test-retest reliability with a high intraclass correlation coefficient (0.89) and Pearson's correlation (r= 0.82, P < .0001). The 12-item CRS-PRO correlated highly with the longer SNOT-22 (r= 0.83, P < .0001) demonstrating its concurrent validity. We also demonstrated validity and reliability in a separate analysis for patients with CRSsNP and CRSwNP. The CRS-PRO is a concise, valid, and reliable measure that was developed with extensive input from patients with CRS with current disease definitions.