Validation of Control Classifications Using the Chronic Rhinosinusitis Control Test as Comprehensive Reflections of Disease Burden

BACKGROUND: The Chronic Rhinosinusitis Control Test (CRCT) is a validated patient-reported outcome measure that can be used to classify chronic rhinosinusitis (CRS) as controlled, partly controlled, or uncontrolled. OBJECTIVE: To demonstrate correspondence of these CRS control classifications with recognized clinical benchmarks for CRS disease burden. METHODS: A total of 699 patients with CRS were recruited, each of whom completed the CRCT, the overall symptom severity (OSS) scale, a 22-Item Sinonasal Outcome Test (SNOT-22), and the five-level EuroQol questionnaire visual analog scale (EQ-5D VAS). We used the modified Lund-Kennedy (MLK) score to measure endoscopic burden of disease. The OSS, SNOT-22, EQ-5D VAS, and MLK scores were compared across participants whose CRS was classified by the CRCT as controlled, partly controlled, or uncontrolled. RESULTS: The OSS, SNOT-22, EQ-5D VAS, and MLK scores were significantly different across all levels of CRS control (P < .001 on the Kruskal-Wallis H test, and P < .001 for all post hoc tests). Participants with controlled CRS had OSS traditionally associated with mild, controlled symptoms, QOL associated with minimal disease impact, and endoscopic findings largely considered to reflect endoscopically controlled disease. Participants with uncontrolled CRS had OSS associated with severe, uncontrolled symptoms, QOL reflecting significant disease impact, and endoscopic findings considered to reflect endoscopically uncontrolled disease. Participants with partly controlled CRS exhibited intermediate levels of CRS burden. CONCLUSIONS: The classifications of CRS as controlled, partly controlled, and uncontrolled using the CRCT correspond to appropriate benchmarks of CRS symptom severity, QOL impact, and endoscopic burden of disease to provide a comprehensive reflection of a patient's disease state.