June 2004 Volume 68	Number 6

How Many Rooms Do We Need?

Karin Bierstein, J.D.
Assistant Director of Governmental Affairs (Regulatory)


Staffing the correct number of operating rooms (O.R.s) is a recurring issue for anesthesiology groups and hospitals. Leaders of the Kentucky/Ohio Anesthesia Managers Association (KOAMA) have developed a spreadsheet to determine the efficiency of various staffing models, which they have permitted us to place as a download on the ASA Web site. The spreadsheet and its potential uses are described below. The individuals responsible for this tool are: Michael J. Monea, President, Central Anesthesia Management Services, Inc.; Joe Laden, Business Manager, Anesthesia Associates of Louisville, PSC; Carey H. Costantini, M.D., Independent Anesthesiologists, Edgewood, Kentucky; W. David Ackley, CPA, MBA, President, Medical Account Services, Inc.; Robert Ison, Programming, Central Anesthesia Management Services, Inc.


Reporting O.R. Utilization
In a perfect world, all surgical cases would occur during the weekday prime shift and without gaps between cases. All O.R.s would be utilized for eight hours every day. Anesthesiologists would be able to bill for nearly 100 percent of their time spent in the hospital and leave work at a reasonable time and incur no overtime costs.

This does not occur in the real world, and there is a cost to the physicians for less-than-perfect O.R. scheduling efficiency. The following are some of the factors that preclude 100-percent utilization rates:

• O.R. turnover times;
• Cases that start late;
• Cases that are canceled;
• Cases that are finished early, leaving gaps in the schedule;
• Cases that finish after the end of the prime shift;
• Cases that are scheduled after the end of the prime shift;
• Gaps in the schedule; and
• Emergency cases.

Since it is unreasonable to expect 100-percent utilization rates, the question is: What is the most efficient or realistic level of utilization for a given hospital?

From an anesthesiology group’s perspective, optimal utilization rates may range from around 75 percent to 85 percent. For the hospital, however, scheduling efficiency may be less important. In an extremely competitive environment where there is an abundance of available O.R.s, the pressure to make prime surgical time available, usually from 7 a.m. to noon, can be intense. Hospitals may find it necessary to operate at utilization rates far lower than 75 percent just to maintain their referral base of surgeons. When this happens, the anesthesiology practice shares the inefficiency, and when the inefficiency reaches a certain level, the financial burden upon the anesthesiologists can lead to revolt and to requests for stipends from the hospital.

The strategies an anesthesiology group may develop to address its individual situation will depend on many variables. Some of the strategies will probably involve the hospital. Discussions with the hospital will include a review and presentation of utilization data with recommendations for changes and/or requests for financial support.

The presentation of the utilization data can include charts, graphs and trend analyses. Figures 1 and 2 show typical examples.

Click image to enlarge

The two charts give a wealth of detail and precision. Viewers can check the exact utilization of individual O.R.s as well as entire suites for a given time period. The complexity of these typical reports, the volume of data and the time necessary to review the information and consider options, though, tend to reduce their usefulness in convincing the hospital administration of the need for changes in utilization or stipends to compensate the anesthesiology practice for the costs of nonbillable clinical staff time, or both.

O.R. Utilization Spreadsheet
Accordingly the leadership of KOAMA decided to develop additional reporting tools to use during internal discussions as well as in reports to and meetings with hospital administration. One of these tools is an O.R. utilization spreadsheet that, in KOAMA’s opinion, has increased the effectiveness of their presentations to their groups’ hospitals.

KOAMA has generously made the spreadsheet available to the entire ASA membership. A copy of the spreadsheet, which requires Microsoft Excel software, is available on the ASA Web site at <www.ASAhq.org/Washington/pmorrates.htm >. Users should note that neither ASA nor KOAMA makes any representation regarding the benefits or accuracy of the spreadsheet and that we are not able to provide any user support. The authors will consider suggestions for improving the spreadsheet. Also note that the O.R. utilization spreadsheet does not provide the same degree of precision as do more traditional reports. Many additional variables could be included, such as obstetrical anesthesiology services, which would be subject to their own calculations. The spreadsheet provides a mechanism, however, to understand surgical anesthesia staffing and management options with reasonable accuracy.

For the purposes of this exercise, KOAMA defines an O.R. utilization rate as the sum of reported (sometimes, but not always, synonymous with “billed”) anesthesia time and turnover time between cases divided by the total amount of scheduled O.R. time plus overtime. (Overtime is added so that the denominator will reflect the total time that the O.R. was staffed.)

To illustrate: Consider a two-O.R. facility for which you want to determine the utilization rate over the 10-hour time frame from 7 a.m. until 5 p.m. If the two O.R.s are scheduled for eight hours (7 a.m. to 3 p.m.) and 10 hours (7 a.m. to 5 p.m.), respectively, the total amount of available O.R. time will equal 18 hours. To determine utilization for those two O.R.s for one day, calculate total billed minutes within the 10-hour period being reviewed, plus turnover minutes, divided by total regularly scheduled hours plus any overtime minutes after the early room is scheduled to shut down. For example:

An explanation of the handling of overtime: As noted in the above example, where an O.R. scheduled for eight hours of use generates one-half hour of staff overtime, it is as if this room becomes, on this day, an eight and one-half-hour room. Overtime hours are not factored into the utilization program when: 1) those hours fall outside the daily time frame being reviewed or 2) a room is covered by a provider who is not compensated for overtime.

Data required: The fundamental data of utilization tracking are total reported minutes and total cases. For purposes of determining optimal utilization rates during normal operating hours — at night and on weekends, the number of staffed O.R.s will be fixed — only the totals for normal workdays should be included.

Some anesthesiology practice management programs can automatically exclude after-hours, weekend and holiday activities. Other programs do not have this capability. If your system cannot exclude after-hours, weekend and holiday activities, then you will need to determine the percentage of your total reported time generated outside of the normal workday. This number can be estimated from experience or by a sampling of daily anesthesia billing records.

You will need to collect the following data for your spreadsheet:

1. Start and stop date: The spreadsheet will automatically exclude weekends;

2. Number of weekday holidays with an accompanying decreased surgical schedule (e.g., only one O.R. open);

3. Total number of reported anesthesia minutes plus total number of cases done during the normal daily hours being reviewed, i.e., 7:30 a.m. to 7:30 p.m., over the relevant time period, e.g., one year. Weekend, holiday and after-hours data are excluded. (Note: If your anesthesia billing program cannot calculate this value, then use the total number of cases and total reported time discounted by a percentage estimation of the total number of weekend, holiday and after-hours services.);

4. Average room turnover time in minutes per case. If the hospital cannot supply this data, one of your physicians probably can give you a good estimate. (This estimate may be a weighted average; an O.R. used for open-heart procedures can have a turnover time of 25 minutes whereas a room used for “smaller” cases such as pediatric tonsils and adenoids may only require 10 minutes of turnaround time.);

5. Total overtime hours;

6. Number of eight-hour, 10-hour and 12-hour (or other hour block, e.g., six-hour, nine-hour) rooms for which the anesthesiology group routinely provides either physician or nurse anesthetist or anesthesiologist assistant coverage. (Note: The downloadable spreadsheet allows you to plug in the hour blocks used in your hospital.)

Table 1 shows the data from one sample hospital as entered into the spreadsheet. The row headed “Hosp/Var #1” represents the actual hours of use divided by the O.R. hours available. In this example, the practice management software has reported all time and case data so it is necessary to enter the number of holidays included in the analysis period as well as a percentage estimation of holiday, after-hour and weekend data. The practice in the example has entered five vacation days in Column D and a 6-percent adjustment factor in column E. The row labeled “Hosp/Var #1” contains altered, hypothetical numbers of turnover minutes and eight-hour, 10-hour and 12-hour rooms. The user could enter a second set of alternative hypothetical turnover minutes and rooms in use in the rows labeled “Hosp/Var # 2,” “Hosp/Var # 3,” etc.

Table 2 automatically transforms the raw data from Table 1 into results. Thus the utilization rate over the 12-month period covered, based on the numbers of eight-hour, 10-hour and 12-hour rooms that the hospital wants staffed, is 60.43 percent. The changes to the room turnover time (from 25 minutes average to 15 minutes average) and to the number of rooms staffed yield a higher utilization rate of 72.46 percent. If the group was seeking an even higher rate, it would need to shorten turnover time further and reduce the number of rooms staffed again, both of which would, of course, require hospital cooperation.

The final two columns in Table 2 indicate the reduction in the number of O.R.s or the increase in the number of daily cases that would be required to achieve a utilization rate of 100 percent.

Click image to enlarge

Using the spreadsheet. The spreadsheet allows anesthesiology practices to compute the actual O.R. utilization rate at their hospital over any period of time. More importantly a practice may model more efficient scheduling patterns and utilization rates by varying turnover times and the number of O.R.s that it must staff during normal hours. Other possible uses include:

• Examining (benchmarking) multiple hospitals or sites simultaneously; and
  
  
• Reviewing utilization for specific periods of time; e.g., an eight-hour utilization rate could be derived from total cases and total reported time for the eight-hour period of interest, i.e., 7:30 a.m. to 3:30 p.m., by placing the total number of rooms in the eight-hour column.

The spreadsheet has turned out to be a powerful tool. The KOAMA developers have found that it makes it easier to determine and justify their groups’ income and staffing needs. It allows the groups to present recommendations regarding the number of O.R.s, hours scheduled, requests for income support and requests for additional staff to their hospitals. Using a laptop computer and projector at a meeting, they have demonstrated different scenarios using historical data by changing variables such as the number of O.R.s, room schedules and turnover time. The spreadsheet dynamically recalculates O.R. utilization.

In the words of the developers, “It is with pleasure that we share this with our friends and colleagues.”