Because nonattendance of outpatients scheduled for GI endoscopy is unavoidable, a frequently recommended solution involves overbooking patient appointments.

To provide a set of numerical guidelines of how to overbook patients scheduled for endoscopy.

Cost-benefit analysis using stochastic modeling to estimate the total number of endoscopy appointments (including overbooking) that maximize the expected benefit from endoscopy.

Subjects scheduled for GI endoscopy.

The number of endoscopies that should be scheduled under various scenarios of patient attendance rates, the number of available endoscopy slots, and the cost impact of missed appointments.

Overbooking can increase the expected benefit but never quite reaches the benefit that would be achieved, if all patients were perfectly reliable in meeting their scheduled appointments. The expected benefit of overbooking always comes to lie between the low benefit without overbooking and the high benefit associated with perfectly reliable patients. The less reliable the patient population, the more overbooking needs to take place. Overbooking should also expand with a decreasing cost impact of overbooked endoscopies. Overbooking is most beneficial in large endoscopy units. This article provides a table with a large set of numerical examples for different scenarios of overbooking that cover endoscopy units of diverse sizes and patient attendance rates.

The analysis does not take into account individual patient characteristics that may affect attendance rates.

This analysis yields a set of estimates for overbooking that can be readily applied to a large variety of endoscopic units.