What is triage?

Triage is the practice of ranking patients by how urgently they need care, so that scarce staff, beds and time go first to those who benefit most. It is used in emergency departments and in disasters. Its purpose is to make the best use of limited capacity instead of treating people strictly in order of arrival.

How it works

On arrival, a nurse or clinician assigns each patient a category, such as immediate, urgent, delayed or non-urgent, based on symptoms and vital signs. Treatment capacity is then offered to the highest category first, with lower categories waiting longer.

The trade-off is between the speed for the most severe and the delay for the rest. Triage works well when the sorting is accurate, but a mistake in either direction has costs: a serious case sent to a long wait can deteriorate, and a minor case marked urgent takes capacity from someone who needs it more. Waits for low-priority patients can become long when high-priority arrivals are frequent.

Example

Say an emergency department has 2 treatment spaces, and each patient needs 1 hour. In one hour, 6 patients arrive: 1 immediate, 2 urgent and 3 non-urgent. Treating by arrival order, the immediate patient might be 5th in line and wait 2 hours. With triage, the immediate patient goes first with no wait, the two urgent patients are next, and the three non-urgent patients wait the longest, about 2 hours each. The total capacity is the same, but waiting is moved to those who can bear it. This is an illustration.

How to model it in Machinations

Use a Source for arrivals and a Gate with probabilities to split them into categories. Each category goes to its own Queue, and a Pool of treatment capacity serves them in priority order, using conditions to check higher queues first. Make the share of severe arrivals and capacity Levers, then Play and chart waiting time per category.