Visual Encoding:
The model displays primary care providers (PCPs) as circles on randomized positions within each district. The size of the circle indicates the current activity, i.e., the average number of patients per quarter, of a PCP. The color of a circle indicates the current capacity of a PCP on a scale from green (average activity) to red (activity at at maximum capacity). Hovering the mouse pointer over a circle displays a pop-up window with more detailed information on the activity. When clicking a circle, links to the direct neighbors in the patient-sharing network of the corresponding PCP are displayed. To indicate the probability, based on which a patient would move from PCP i to PCP j, the thickness of each link is scaled by the respective probability value.

Removing a PCP:
When long-clicking (or SHIFT-clicking) on a circle, the respective PCP is removed from the model and the doctor's activity is distributed across the patient-sharing network. The distribution is indicated through an animation, drawing links between the removed PCP and the PCPs that are adjacent in the patient-sharing network. In order to indicate the increased activity of PCP j, the corresponding circle will grow in size accordingly. The circle will also adapt its color to indicate how much closer the PCP is to maximum capacity due to the increased activity. If a PCP cannot accept all incoming patients, a new wave of distributions is triggered by drawing links from PCP j to its adjacent neighbors, resulting in a new cascade of links for each PCP that cannot accept all incoming patients. In order to visually distinguish each wave of patient referrals, the links of each wave are drawn in a distinct color.