Case‐Mix Moderation of the Relationship Between OR Performance Metrics and Utilization

Abstract

We investigated the impact of the case-mix ratio of inpatients to outpatients on the relationships between OR utilization and late starts, turnover time, delays, cancellations, and idle time at an academic medical center in the southeastern United States. After extracting 55 months of data from the surgical repository, we used simple and multiple linear regression models to analyze the data and determine the strength and direction of the relationships among the variables. We compared models comprising proportionally more inpatients to models comprising proportionally more outpatients for each metric to ascertain the effects of case mix on OR utilization. Idle time had the greatest effect on OR utilization, followed by late starts and turnover time. Case mix moderated the relationship between OR utilization and the metrics of cancellations and turnover time. Perioperative leaders may enhance OR utilization by monitoring and addressing idle time and late starts and scheduling an appropriate mix of inpatients and outpatients.

Retrospective Analysis of Associated Costs and Sources of Variability in OR Utilization Across Weekdays

“…Late starts occur when patients are transported into the OR for the first procedure of the day after the scheduled start time on the surgery schedule. 20 Delays occur when the time between procedures exceeds the planned turnover time-the time to clean the room and prepare it for the next procedure on the schedule. Idle time refers to the unused time at the end of the OR's standard business hours, during which an OR is empty but routinely scheduled OR personnel are still working.…”

“…Idle time refers to the unused time at the end of the OR's standard business hours, during which an OR is empty but routinely scheduled OR personnel are still working. 20 The metric of turnover time is typically included in OR utilization.…”

“…Some performance indicators that perioperative managers monitor include the number of minutes associated with late starts, delays, and idle time. Late starts occur when patients are transported into the OR for the first procedure of the day after the scheduled start time on the surgery schedule 20 . Delays occur when the time between procedures exceeds the planned turnover time —the time to clean the room and prepare it for the next procedure on the schedule.…”

“…Delays occur when the time between procedures exceeds the planned turnover time —the time to clean the room and prepare it for the next procedure on the schedule. Idle time refers to the unused time at the end of the OR's standard business hours, during which an OR is empty but routinely scheduled OR personnel are still working 20 . The metric of turnover time is typically included in OR utilization.…”

Operating Room Allocation and Case Scheduling Have the Largest Effect on Underutilized Time

“…In the article, "Case-mix moderation of the relationship between OR performance metrics and utilization," 1 in the December 2022 issue of the AORN Journal (Vol 116, No 6), Elliott-Dawe et al examined variability in percentages of OR utilization. According to their introduction, "…with the exception of a single study completed in the Netherlands, the interrelationship of all performance metrics and their effects on OR utilization remain undescribed."…”