The 'Surgical Time': a myth or reality? Surgeons' prediction of operating time and its effect on theatre scheduling
Authors: Goel Raghav , Kanhere Harsh , Trochsler Markus 
Published: September 2020

ObjectiveIn Australia, 2.7 million surgical procedures were performed in the year 2016–17. This number is ever increasing and requires effective management of operating theatre (OT) time. Preoperative prediction of theatre time is one of the main constituents of OT scheduling, and anecdotal evidence suggests that surgeons grossly underestimate predicted surgical time. The aim of this study is to assess surgeons’ accuracy at predicting OT times across different specialties and effective theatre scheduling.
MethodsA database was created with de-identified patient information from a 3-month period (late 2016). The collected data included variables such as the predicted time, actual surgery time, and type of procedure (i.e. Emergency or Elective). These data were used to make quantifiable comparisons.
ResultsData were categorised into a ‘Theatre list’ and ‘Scopes list’. This was further compared as ‘Actual–Predicted’ time, which ranged from an average underestimation of each procedure by 19min (Ear Nose and Throat surgeons) to an average overprediction of 13.5min (Plastic Surgery). Urgency of procedures (i.e. Emergency and Elective procedures) did not influence prediction time for the ‘Theatre list’, but did so for the ‘Scopes list’ (P&lt;0.001). Surgeons were poor at predicting OT times for complex operations and patients with high American Society of Anaesthesiologists grades. Overall, surgeons were fairly accurate with their OT prediction times across 1450 procedures, with an average underestimation of only 2.3 min.
ConclusionsIn terms of global performance at The Queen Elizabeth Hospital institution, surgeons are fairly accurate at predicting OT times. Surgeons’ estimates should be used in planning theatre lists to avoid unnecessary over or underutilisation of resources.
What is known about the topic?It is known that variables such as theatre changeover times and anaesthesia time are some of the factors that delay the scheduled start time of an OT. Furthermore, operating time depends on the personnel within the operating rooms such as the nursing staff, anaesthesiologists, team setup and day of time. Studies outside of Australia have shown that prediction models for OT times using individual characteristics and the surgeon’s estimate are effective.
What does this paper add?This paper advocates for surgeons’ predicted OT time to be included in the process of theatre scheduling, which currently does not take place. It also provides analysis of a wide range of surgical specialties and assesses each professions’ ability to accurately predict the surgical time. This study encompasses a substantial number of procedures. Moreover, it compares endoscopic procedures separately to laparoscopic/open procedures. It contributes how different variables such as the urgency of procedure (Emergency/Elective), estimated length of procedure and patient comorbidities affect the prediction of OT time.
What are the implications for practitioners?This will encourage hospital administrators to use surgeons’ predicted OT time in calculations for scheduling theatre lists. This will facilitate more accurate predictions of OT time and ensure that theatre lists are not over or underutilised. Moreover, surgeons will be encouraged to make OT time predictions with serious consideration, after understanding its effect on theatre scheduling and associated costs. Hence, the aim is to try to make an estimation of OT time, which is closer to the actual time required.