Determining optimum operating room utilization.

UNLABELLED: Economic considerations suggest that it is desirable to keep operating rooms fully used when staffed, but the optimum utilization of an operating room (OR) is not known. We created a simulation of an OR to define optimum utilization. We set operational goals of having cases start within 15 min of the scheduled time and of having the cases end no more than 15 min past the scheduled end of the day. Within these goals, a utilization of 85% to 90% is the highest that can be achieved without delay or running late. Increasing the variability of case duration decreases the utilization that can be achieved within these targets. IMPLICATIONS: Using a simulated operating room (OR), the authors demonstrate that OR utilization higher than 85% to 90% leads to patient delays and staff overtime. Increased efficiency of an OR comes at a cost of patient convenience.