Figure 2.

Validation of qPCR-based classifier in independent cohorts. (A and B) Kaplan-Meier plots of escalation-free survival for the CD validation cohort (A; n=66) and the UC validation cohort (B; n=57) as stratified by the IBDhi (IBD1 equivalent) and IBDlo (IBD2 equivalent) patient subgroups. Data are censored at 18 months. Statistical significance assessed by log-rank test. (C and D) Stacked density plots demonstrating the maximum medical therapy that was required during the first 2.5 years’ prospective follow-up of the IBDhi and IBDlo subgroups in CD (C) and UC (D). Treatments were plotted hierarchically (no treatment<immunomodulator<anti-TNFα<second-line biologicals (vedolizumab or ustekinumab) in CD and 5-ASA only<immunomodulator<anti-TNFα<vedolizumab < colectomy in UC). Arrows represent episodes of surgery that were required for CD patients at the indicated timepoints. Data are censored accordingly to length of follow-up so that the denominator is the total available cohort at each timepoint. (E and F) Forest plots of the relative risk (IBDhi vs IBDlo) of requiring no treatment escalations, one treatment escalation or two or more treatment escalations within the first 18 months after enrolment for patients with CD (E) and patients with UC (F). Relative risk is with respect to the IBDhi subgroup in each disease and is presented separately for the training cohort, validation cohort and combined cohorts. Error bars indicate 95% CIs. CD, Crohn’s disease.