Title:
Criteria for assessing operating room utilization in a free-standing children's hospital.

Abstract:
The staffed hours of operation in any surgical facility are a valuable institutional resource. The realistic target for the utilization of this resource is dependent on many factors including scheduling, efficiency, and culture of the facility. There is no previously reported measure for the actual utilization of staffed regular operating room (OR) hours in an academic pediatric institution. The leadership of the perioperative services at Children's Hospital Boston (CHB) sought to define the utilization of surgical suite staffed block time hours at that institution and in addition determine whether changes in workflow could increase the measured utilization.
Operating room efficiency in fiscal year 2009 was measured using two variables: utilization and turnover measured in hours for each month in fiscal year 2009, recorded in hours expressed as ratios (observed/expected) and as differences (observed - expected). A total of 27,851 cases from October 1, 2008, through September 30, 2009, were analyzed. All elective cases were scheduled electronically following institutional guidelines; urgent or emergent procedures were scheduled into vacant time slots on the day of the procedure. Time series analysis based on a generalized autoregressive moving average process was used to compare expected with observed utilization and to evaluate changes in utilization and turnover ratios.
Efficiency as measured by capped utilization divided by total available time in the OR averaged 79%. Utilization ratios ranged from a low of 73% in February 2009 to a high of 87% in July 2009. An improvement in on-time first-case starts may have contributed to the increase in the utilization of staffed block time. Turnover time as defined by turnover ratio decreased significantly over time, indicating an improved efficiency in the OR starting in April 2009.
Adhering to the specific guidelines that are followed at CHB, the mean utilization of scheduled block time was 79%. This was achieved by maximizing workflow in the surgical, anesthesia, and nursing disciplines to shorten turnover time, fill gaps in the elective schedule with emergency procedures, and provide staffing to accommodate cases that extend beyond the scheduled staffed time prior to the reporting period. Simulated models from other pediatric institutions suggest that the optimal utilization of designated time periods in a surgical facility may range from 85% to 90%.