Letter to the Editor: Plasma proteomic markers predict risk for bowel resection in inflammatory bowel disease: a retrospective cohort study

To the Editor: We read with interest the article by Xu et al in the International Journal of Surgery, “Plasma Proteomic Markers Predict Risk for Bowel Resection in Inflammatory Bowel Disease: A Retrospective Cohort Study”[1]. Using plasma proteomics from the UK Biobank Pharma Proteomics Project and a random survival forest (RSF) approach, the authors report that an inflammation-related protein signature predicts subsequent bowel resection in inflammatory bowel disease (IBD) better than conventional clinical markers. We commend the authors for tackling long-term surgical risk stratification with a scalable proteomics-based framework. To further strengthen interpretability, reproducibility, and clinical translation, we offer several constructive comments. First, the definition and directionality of the “predicted risk score” require clearer specification. The Methods describe transforming RSF-derived survival probabilities into a continuous score, with higher values indicating higher predicted resection risk and using the median to define high/low-risk groups for Kaplan–Meier analyses. However, the baseline table refers to the score as the “probability of remaining surgery-free,” while the reported medians (e.g., 2.70 vs 7.58) do not align with a 0–1 probability scale. In addition, the adjusted hazard ratio for the score in multivariable Cox regression is