Development of a Clinically Relevant Endoscopic Grading System for Chronic Rhinosinusitis Using Canonical Correlation Analysis

Background Diagnostic nasal endoscopy is a routine measure of sinonasal inflammation in patients with chronic rhinosinusitis (CRS). Although multiple staging systems have been proposed and evaluated, evidence of association between concurrent symptoms and endoscopic findings remains discordant. The goal of this study is to identify the relevant endoscopic attributes associated with symptom burden, and to systematically derive a weighted endoscopic scale that optimizes prediction of concurrent symptoms. Methods Reported baseline symptom (22-item Sino-Nasal Outcome Test [SNOT-22]) and endoscopic evaluation scores (Lund-Kennedy [LK]) were obtained from patients with CRS enrolled in a prospective cohort study. Canonical correlation analysis of the SNOT-22 subdomains and LK variables was completed. Results A total of 629 patients were included in analysis including 343 with prior endoscopic sinus surgery. Significant canonical correlations outperformed aggregate correlations in explaining variance of the data (33% vs 3%, respectively). The first canonical correlation was dominated by the rhinologic symptom domain and the endoscopic polyp score (r = 0.54; p \u3c 0.05) whereas additional significant canonical correlation was found between the extra-rhinologic symptom subdomain and the edema score in patients without prior ESS (r = 0.21; p \u3c 0.05), and discharge in patients with prior ESS (r = 0.22; p \u3c 0.05). All other domains and endoscopic variables did not significantly contribute to the canonical correlation. Conclusion Although aggregate symptoms and endoscopic scores demonstrate minimal correlation, a weighted combination of symptom domains and endoscopic attributes greatly improves this correlation. A simple approximation of the weights of each of the endoscopic variables of polyps, edema, discharge, scarring, and crusting, is an approximate ratio of 4:2:1:0:0, respectively

Defining the Minimal Clinically Important Difference for Olfactory Outcomes in the Surgical Treatment of Chronic Rhinosinusitis

Background Olfactory dysfunction is a common and defining symptom of chronic rhinosinusitis (CRS). Many measures of olfactory dysfunction in CRS are limited by scoring criteria defined within general populations with interpretations of statistical significance to infer clinically meaningful improvement. In this investigation we define a minimal clinically important difference (MCID) for the Brief Smell Identification Test (BSIT) in CRS patients electing endoscopic sinus surgery (ESS). Methods: A multicenter cohort of 290 adult patients electing ESS for medically recalcitrant CRS were prospectively enrolled between March 2011 and June 2015 and completed BSIT evaluations before and after ESS. Distribution and anchor-based analytic approaches were utilized to define MCID values of the BSIT across patient cofactors. Results: A total of 92 (∽32%) patients were found to have preoperative olfactory dysfunction (BSIT \u3c 9), significantly associated with nasal polyposis (χ(2) = 35.0; p \u3c 0.001). The effect-size distribution-based approach identified 1.0 as a MCID criterion value between small and medium effect (range, 0.61-1.52) overall. Significant mean postoperative change (ΔM) was reported for patients with olfactory dysfunction (ΔM = 2.28; p \u3c 0.001), both with (n = 54; ΔM = 2.52; p \u3c 0.001) and without (n = 38; ΔM = 1.95; p \u3c 0.001) nasal polyposis, significantly exceeding the MCID criterion. Anchor-based approaches with regression modeling confirmed associations between MCID values and postoperative changes to olfactory-specific survey responses (p \u3c 0.001). Conclusion: Clinically meaningful change in BSIT scores may be defined as an absolute value difference of at least 1.0 unit for heterogeneous patients electing ESS for CRS. Significantly exceeding this criterion may be restricted to CRS patients with baseline olfactory dysfunction, regardless of nasal polyposis. PMID: 28556611 [PubMed - as supplied by publisher

Investigating the Minimal Clinically Important Difference for SNOT-22 Symptom Domains in Surgically Managed Chronic Rhinosinusitis

Background: Prior work has described 5 domains within the 22-item Sino-Nasal Outcomes Test (SNOT-22) that allow for stratification of symptoms into similar clusters and that can be used to direct therapy. Although the outcomes of various interventions on these symptom domains have been reported, minimal clinically important difference (MCID) values have not been investigated, which has limited clinical interpretation of these results. Methods: This study was designed as a secondary analysis of a prospective, multi-institutional, observational cohort. A total of 276 patients with medically refractory CRS who underwent surgical management were enrolled. Distribution-based methods (half-standard deviation, standard error of measurement, Cohen\u27s d, and the minimum detectable change) were used to compute MCID values for both SNOT-22 total and domain scores. The Medical Outcomes Study Short Form 6D (SF-6D) health utility score was used to operationalize anchor-based associations using receiver-operating characteristic (ROC) curves. Results: The mean MCID of several distribution-based methods for total SNOT-22 scores was 9.0, in agreement with previously published metrics. Average MCID values for the rhinologic, extranasal rhinologic, ear/facial, psychological, and sleep domain scores were 3.8, 2.4, 3.2, 3.9, and 2.9, respectively. Anchor-based approaches with the SF-6D did not have strong predictive accuracy across total SNOT-22 scores or domains (ROC areas under-the-curve ≤ 0.71), indicating weak associations between improvement in SNOT-22 scores and health utility as measured by the SF-6D. Conclusion: This estimation of MCID values for the SNOT-22 symptom domains allows for improved clinical interpretation of results from past, present, and future rhinologic outcomes research