Congratulations to @LauraBukavinaMD @jaymsiva @drjkaouk and @ClevelandClinic team on largest external validation of the IBCG IR NMIBC substratification model 📊 2822 patients | 20 years | 3-year recurrence by subgroup: 🟢 IR-low: 12% 🟡 IR-intermediate: 38% 🔴 IR-high: 77% Progression followed the same stepwise pattern. Fine-Gray competing-risk models confirmed significance (p<0.001) - separation held on 12-month landmark analysis, ruling out early-event bias. Yet more evidence that trials enrolling IR NMIBC should stratify by IBCG subgroup at enrollment to be clinically meaningful. Conflating patients with 12% and 77% recurrence risk in the same trial arm is a fundamental problem. Full text: authors.elsevier.com/sd/arti… @IBCG_BladderCA