A New Model to Predict Survival in Patients with Refractory Celiac Disease (MRCD): Results from a Multinational Study

Abstract

Purpose: Refractory celiac disease (RCD) is a severe complication of celiac disease. The aim of the study was to develop a new model to estimate survival of patients with RCD (MRCD). Methods: From a multinational registry of RCD patients, seven pre-selected variables were evaluated as predictors of 5-year mortality using Cox proportional hazards regression on the pooled set of subjects. To internally validate the individual factors and overall model performance, we used bootstrap re-sampling. With each bootstrap sample, the full multivariable model was estimated (training model) and then applied to the original sample to assess performance (testing model). To correct for bias in the original model fitting, we estimated the optimism in model accuracy as the average difference between training and test model c-statistic values. Regression coefficients from the final multivariable model were used to derive a risk score for 5-year mortality. Results: The multinational cohort was composed of 233 subjects across 7 centers (5 countries), with 150 (64%) women and a median age of 53 years (range, 15-88 years). One subject was excluded from the risk factor analyses due to lack of follow-up. Despite significant differences in several factors across the 7 centers, the rates of 5-year mortality did not differ significantly (p=0.41). The risk of 5-year mortality from the original multivariable model is summarized in Table 1 (apparent and bias-corrected model c-statistic was 0.756 and 0.725, respectively). The risk score point system (score range 0-14) is summarized in Table 2. Kaplan-Meier rates of survival are plotted by risk score quartiles in Figure (5-year survival 100% for score 0-4, 68-77% for score 5-9, and 38% for score 10-14).Table 1: Summary of variables and size of risk (Multivariable Model)Table 2: Risk score point systemFigure: [1469] Figure. Kaplan-Meier survival curves by risk score quartiles.Conclusion: The new MRCD score may be useful to estimate 5-year mortality risk in patients with RCD and may help guide therapeutic interventions in this most serious complication of celiac disease.