Report 25

Operating Theatre Efficiency

Introduction and Background


This report provides an assessment of how efficiently five public hospitals used operating theatres to deliver elective surgery over a six year period from 2009 to 2014.

To assess efficiency, we analysed the proportion of time operating theatres were used for surgery, across each hospital and also by surgical speciality. Late starts and lengthy gaps between scheduled surgical cases are examples of inefficiencies. We took into consideration the need for turnaround time between cases and that some delays and cancellations are outside a hospital’s control. The average theatre time for cases in elective sessions in our sample was 70 minutes. Therefore, we have reported on significant late starts and early finishes greater than one hour. We considered whether hospitals could do more procedures with the same resources. We engaged a subject expert to review the evidence and contribute to the findings. The audit did not assess clinical processes or outcomes.


Improving operating theatre efficiency can increase the number of patients treated with the same level of resources. This can save money, enable hospitals to manage their wait list and reduce the time patients have to wait for surgery.

Western Australia (WA) has 112 operating theatres within 32 public hospitals, plus additional theatres in two privately operated public hospitals. Operating theatres are used for elective and emergency surgery. The procedures performed depend on the clinical services provided at each hospital.

This audit focused on elective surgery, which is surgery that is medically necessary but does not have to be performed within 24 hours of diagnosis. The waiting time for elective surgery is driven by demand, clinical need and the availability of the facilities and people needed to deliver both the operation and after care. Common examples of elective surgery are removal of tonsils, hip replacements and cataract surgery.

Hospitals schedule elective surgery in advance in morning, afternoon or all-day blocks called sessions. Sessions are allocated to either elective or emergency surgery and to particular specialties such as orthopaedics and urology, depending on the hospital’s clinical services. Hospitals or the surgeon’s staff book patients into sessions based on their assessment of the time it will take to treat the patients. Starting and finishing times of sessions vary between hospitals. Sessions that end late can result in overtime payments for some staff.

A session can contain one or more cases, and a single case may involve multiple surgical procedures. The time between two cases in a session when hospital staff clean and prepare the theatre for the next case is termed ‘turnaround time’.

Figure 1 - Components that make up an elective surgery session

The five public hospitals we reviewed capture data that tracks a patient’s journey through the operating theatre, enabling measurement of efficiency. We used the data to review performance against six measures to conclude on the operating theatres’ efficiency:

  • theatre utilisation (the proportion of time patients are in theatre within a scheduled session)
  • on time starts for the first case
  • sessions that finish early
  • sessions that finish late
  • day of surgery cancellations
  • average turnaround time between cases.

We recognise that the value of improving operating theatre efficiency is debateable if other patient flow factors are not met, such as having sufficient recovery beds available after surgery. Nevertheless, improving operating theatre efficiency and related practices such as patient bookings and operating schedules can deliver significant benefits for hospitals and patients, and contribute to reductions in waitlists. Having an accurate view of operating theatre performance and demand also enables hospitals to make more informed decisions about where capacity can be improved within planned sessions.

Page last updated: August 8, 2018

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