Figure 1.

Structure of state transition model. Patients with Crohn’s disease may have different levels of disease activity, included as the CDAI-based health states in the model. Each model week, a patient was predicted to be in one of the health states and could transition from one health state to another based on transition probabilities derived from CALM trial data using a regression model. Hospitalization was included as a toll state. The health states determined patients’ costs, health utility and likelihood of hospitalization.