Effect and Threshold of Endoscopic Findings for CRS Control Status and Long-Term Outcome Prediction

EPOS 2020 defined chronic rhinosinusitis (CRS) disease control using patient symptoms and medication usage but endoscopic findings were considered optional. The effect of adding endoscopic features, an appropriate threshold, and their association with present or future symptom control have not been studied.

A prospective cohort study of 188 adult CRS patients undergoing bilateral endoscopic sinus surgery from 2017 to 2023 was conducted. Patients were assessed at 6-12 months (V1) and 18-60 months (V2) postoperatively. Individual patient symptoms from the SNOT-22, endoscopic findings (modified Lund-Kennedy [MLK] score), and medication usage were recorded. CRS control status was classified as controlled or suboptimal control (EPOS partly/un-controlled) based on EPOS 2020 criteria without endoscopic features. The predictive role of endoscopic findings was analyzed.

Endoscopic findings were weakly associated with concurrent control status but the total MLK (V1 AUC = 0.631, p < 0.001; V2 AUC = 0.620, p < 0.05) outperformed any individual MLK component in strength of association. Adding MLK to V1 control status using a threshold of MLK ≥ 3 marginally improved prediction accuracy for V2 control compared to V1 control status defined without endoscopic features (AUC = 0.744 vs. 0.721, respectively, both p < 0.001).

While endoscopic findings are only weakly associated with concurrent control status, their addition enhances prediction of subsequent V2 CRS outcomes. Our study provides the first real-world evidence supporting the value of endoscopic findings as predictors for CRS disease progression, with an MLK threshold ≥ 3 showing moderate predictive accuracy for future maintenance of control.