Rescheduling of Previously Cancelled Surgical Cases Does Not Increase Variability in Operating Room Workload When Cases Are Scheduled Based on Maximizing Efficiency of Use of Operating Room Time

Abstract

Conceptually, cancelling a case close to the scheduled day of surgery increases variability in operating room (OR) workload (i.e., total hours of scheduled cases plus turnovers), creating managerial problems. However, in our recent study of an OR scheduling office, cancellations (slightly) reduced variability in workload among days. If a relatively low incidence of cancellations does not cause increased variability in workload, this would be a useful finding when focusing strategic OR management initiatives. However, the previous study considered only the effect on the schedule for the day the cancelled case originally was scheduled to be performed, not the future date on which the case was performed. For 90% of cancelled cases, the patient later underwent the same or a similar procedure at the studied hospital. Thus, the OR schedule at 7:00 am each day over 2 years could be used to study case rescheduling. The primary end point, calculated for each surgeon, was the difference of 2 ratios. The first ratio was the proportion of scheduled workload attributable to previously cancelled cases, among all days for which the surgeon's workload exceeded the surgeon's median workload. The second ratio was that proportion among the other days when the surgeon performed at least 1 case. Means ± SEMs were calculated by random effects analysis, stratified by surgeon. From 7:00 am the working day before surgery through the day of surgery, 9.7% ± 0.6% of scheduled OR hours and 9.7% ± 0.5% of cases were cancelled. Among cases performed, 9.5% ± 0.5% of the scheduled hours and 9.5% ± 0.5% of the cases were previously cancelled (i.e., rescheduled to a later date and then performed). Surgeons' median workloads on days with at least 1 case were 8.3 ± 0.2 hours. The percentage of scheduled workload attributable to rescheduled cases was slightly less on days when the surgeon had larger than median workloads (-0.7% ± 0.3%, P = 0.022). Rescheduled cancelled cases did not increase variability in OR workload. This finding is useful combined with our recent finding that cancellation slightly reduces variability in OR workload on the date of cancellation. Cancellations should not be interpreted as a system failure that increases variability in surgical workload. We recommend that anesthesiologists aim to reduce cancellation rates if above benchmarked averages, but otherwise focus on more strategically beneficial initiatives. We recommend also that these results be considered if cancellation rates are used in assessing anesthesiology group performance.