Model assumptions
REMISSION, COMPLICATIONS

All patients who achieved remission would maintain it during the first period (0–3 months).During the second period (4–12 months), patients who achieved the initial remission would either maintain it for the rest of 9 months or if lost responses would undergo colectomy. For patients had colectomies in the second period the model assumed that colectomies occurred mid-period i.e. at 8 months.During the third period (13–24 months), patients who achieved the initial remission would either maintain it for the rest of 12 months or if lost responses would undergo colectomy. Patients who had colectomies in the third period the model assumed that colectomies occurred mid-period i.e. at 18.5 months.After surgery, patients either achieved remission or experienced post-surgery complications immediately after the surgery in the same period. Those treated for post-surgery complications, achieved post-surgery remission in the next period and maintained it for the rest of the analysis.