Calibration, Clinical Utility and Specificity of Clinical Decision Support Tools in Inflammatory Bowel Disease.

Background and aims: Clinical decision support tools (CDSTs) have been developed to predict response to vedolizumab (VDZ) and ustekinumab (UST) in Crohn's disease (CD) and ulcerative colitis (UC). In addition to assessing their discrimination performance, our study aimed to evaluate their calibration, clinical utility and specificity.

Methods: We included 280 CD and 218 UC patients initiating VDZ, and 194 CD patients initiating UST. We assessed discrimination by comparing rates of effectiveness outcomes between response probability groups forecasted by CDSTs. Calibration curves and decision curve analysis evaluated the calibration and clinical utility of VDZ-CDSTs. Additionally, we examined the agreement between UST-CDST and VDZ-CDST in assigning response probability groups among CD patients starting UST.

Results: In the overall cohort, CDSTs allocated 7.2%, 50.0% and 42.8% of the patients to the low, intermediate and high response probability groups, respectively. VDZ-CDSTs groups demonstrated significant differences in the rates of clinical and endoscopic response and remission, while UST-CDST groups showed significant discrimination only for clinical remission. Although VDZ-CDSTs overestimated clinical remission rates, they more accurately predicted rates of VDZ persistence without need for surgery or dose escalation. Compared to empirically treating all patients with VDZ, VDZ-CDSTs yielded higher net benefits in selecting patients who would continue VDZ without need for surgery or dose escalation. Finally, the agreement between UST-CDST and VDZ-CDST in predicting response was 73.7%.

Conclusion: VDZ-CDSTs significantly discriminated response to VDZ and were more beneficial in identifying patients who would continue therapy without requiring surgery or dose escalation, compared to treating all patients empirically.