Selection of Paired Patients

To study the contributions of the less important features that important features may overshadow, we selected the paired patients with controlled discrepancy of important features in the Testing cohort and Validation cohort separately. In this study, for every two patients a and b, the discrepancy was defined as the mean value of absolute relative differences in important features: ∑i=1nabs(fa−fbfmax)/n , where i is the important feature number, n is the total important feature number, abs means absolution, f_a and f_b are the feature values in patients a and b, respectively, and f_max means the maximum of the feature. For each less important feature we need to study, the important features were defined as those with the SHAP values bigger than the less important features. Two patients with a discrepancy less than the threshold and different lymphopenia outcomes were considered one paired patient. In the selected paired patient cohort, we used paired t-test to assess the significance of the less important feature on the lymphopenia events.