Multi-institutional minimal clinically important difference of the 22-item Sinonasal Outcome Test in medically managed chronic rhinosinusitis

Abstract

Background: With a rapid proliferation of clinical trials to study novel medical treatments for CRS, the objective of this study was to study the minimal clinically important difference (MCID) of the 22-item Sinonasal Outcome Test (SNOT-22) in medically-managed CRS patients. Methods: A total of 183 medically-treated CRS patients were recruited. All patients completed a SNOT-22 at enrollment and subsequent follow up visit. Distribution and anchor-based methods were used for MCID calculation. These data were combined with data from a previously published study on SNOT-22 MCID in 247 medically managed CRS patients to determine a final recommended MCID value using the combined cohort of 430 patients. Results: In our cohort, distribution- and anchor-based methods—using both sinus-specific and general health anchors—provided greatest support for a 12-point SNOT-22 MCID, which had approximately 55% sensitivity but 81% specificity for detecting patients explicitly reporting improvement in their sinus symptoms and general health. In the combined cohort of 430 patients, we also found greatest support for a 12-point SNOT-22 MCID, which had approximately 57% sensitivity and 81% specificity for detecting patients explicitly reporting improvement in their sinus symptoms and general health. We also find evidence that the MCID value may be higher in CRS patients without nasal polyps compared to those with nasal polyps. Conclusions: Our results - which include data from patients from two different institutions and regions - confirm a SNOT-22 MCID of 12 in medically managed CRS patients. The SNOT-22 MCID was specific but not sensitive for identifying CRS patients experiencing improvement in symptoms or general health.