Appendix S1 - Estimation of Recurrence of Colorectal Adenomas with Dependent Censoring Using Weighted Logistic Regression

We first derive the bias for the sample proportion estimate and then establish the property of the two working models, which are used to derive the two risk scores to define risk groups for recurrence. The property indicates that within each of the risk groups the recurrence time is asymptotically approximately independent of the censoring time. (DOC)