{Reference Type}: Journal Article {Title}: Retrospective Analysis of Associated Costs and Sources of Variability in OR Utilization Across Weekdays. {Author}: Elliott-Dawe C;Chen J;Stucky CH;Zadinsky JK; {Journal}: AORN J {Volume}: 120 {Issue}: 1 {Year}: 2024 Jul {Factor}: 0.831 {DOI}: 10.1002/aorn.14164 {Abstract}: Few studies have examined variability in OR utilization across weekdays. We conducted a retrospective analysis to determine OR utilization differences by day of the week and the source and financial effects of any variability. We extracted 55 months of data from a surgical data repository to calculate OR utilization, late starts, idle times, and delays for each weekday. Declines in OR utilization occurred as the week progressed and were attributed to compounding changes in late start, delay, and idle time. The average weekly cost for each OR associated with unused staffed minutes below a target OR utilization of 85% was $19,383, and the comparable lost weekly revenue was $60,256. Perioperative leaders should identify sources of OR utilization variability when developing strategies that enhance outcomes for patients, minimize costs, and maximize revenue.