IPS-E stratified TTFT in patients with early-stage CLL managed with active surveillance. (A) Kaplan-Meier curves of TTFT stratified by IPS-E in the UEP discovery cohort. (B) Meta-analytic estimate of TTFT by IPS-E and the corresponding variability across the 9 Binet A validation cohorts. The bold line shows the cubic spline fitted on the meta-analytic estimate of the cumulative proportion of TTFT at each point. The shadow shows the cubic splines fitted on the meta-analytic estimate of the 95% CI of the cumulative proportion of TTFT at each point. (C) Kaplan-Meier curves of TTFT stratified by IPS-E in the Mayo Clinic validation cohort. Blue, low risk; green, intermediate risk; red, high risk by IPS-E. Multiplicity corrected P values by pairwise log-rank tests are shown.