The Epidemiology of Waitlists


Hospital waitlists have become a political problem as well as a practical one for Canadians, but the information available on waiting times is unreliable and gives little sense of how it can be solved. In part this is because there is a poor theoretical basis for understanding waitlists and what causes them to grow in the first place.Orderly waiting (queues) progress in a predictable fashion but waitlists for medical procedures behave less like a queue and more like a pool, in which constant changes in urgency (and therefore priority) occur during the waiting period. Sudden changes in position within an orderly queue are termed "bumping". Occasional bumping incidents can be managed, but when the rate reaches a certain threshold, the orderly process is turned into a chaotic one in which frequent reshuffling and cancellations add both costs and burdens to the system at the same time as they destroy public confidence. There is evidence that this has already occurred in many regions in Canada.This project seeks to explore the mathematical interface between orderly queues and the factors that make them become dysfunctional. The objective is to give health authorities an understanding of the best ways to measure and track waitlists along with strategies for defining and staying within a "safe envelope" instead of trying to deal with bad situations after they have already happened. The research methods will combine the disciplines of queuing theory, statistics, and computer simulation and will include an analysis of Ministry data on real waitlists. Avoiding waitlist chaos will provide better and more reliable health care at the same time as it saves money.