Uncertainty in knowing the operating rooms in which cases were performed has little effect on operating room allocations or efficiency.

UNLABELLED: At many US surgical facilities, applying the previously published method that maximizes the efficiency of use of operating room (OR) time is an effective way to optimize the allocation of OR time. Results are resistant to small errors in recorded OR times. However, at some facilities, the OR information systems data have as much as a 10% error in the correct OR where each case took place. This decreases the total OR time attributed to each service, which is the basis for the allocation method. Such errors could result in incorrect OR allocations and increased OR staffing costs. Expensive and time-consuming data-cleaning steps may be required to resolve the actual OR allocation for each case. We used 1 yr of data from a large, tertiary academic hospital to investigate, through simulation, how increasing levels of error in the correct OR affect OR efficiency and allocations. To apply noise to the data, the actual ORs were changed randomly to unique, "unknown" rooms. At a 30% error level, OR allocations decreased by 4.8%, and costs increased by 1.4% relative to knowing the actual location of every case. Only 1 of 11 surgical services had an allocation decrease at room error rates of less than 25%. We conclude that, in most circumstances, data-cleaning steps to resolve uncertainty in OR locations are not necessary to make accurate OR allocations. IMPLICATIONS: Up to a 30% uncertainty in knowing the actual operating room (OR) in which cases were performed had a minor effect on OR allocations to maximize OR efficiency and on the resulting staffing costs. Thus, facilities with this common error in their OR information systems data will generally be able to use their existing data for accurate OR allocations.