Cancellation of surgery is an inconvenience which has a significant ripple effect. Aside from the obvious waste of theatre time, the impact on patients extends beyond that of the patient whose surgery has been cancelled.In an era where the demand on medical services is disproportionate to the available resources, cancellation of surgery is a costly affair which is often avoidable.This study retrospectively analysed the reasons for cancellation of surgery under the aegis of the Urology Department of Christchurch Hospital in New Zealand.The aim of the study was to identify preventable reasons for cancellation of surgery as well as steps which may minimise their occurrence.Method The study period was between 31 March 2008 and 11 March 2011. Information on the cancelled operations was obtained from the minutes of the Department's weekly audit meetings. This meeting formally documents all cancellations, details their cause and the patient demographic details. The audit coordinator (SJ) classifies the cancellation cause and enters the data on a Microsoft Excel spreadsheet prospectively. A cancellation was deemed to be the unplanned non-occurrence of scheduled surgery in the week of the operation date. Operations that were deferred ahead of time were not included. In the Urology Department, patients are placed on the surgical waiting list either from the outpatient clinic or from the inpatient ward. The decision on whether patients are offered a preadmission clinic appointment is made by the surgical team based on the magnitude of surgery and on the patient's medical comorbidity. Preadmission clinic slots are not available for every patient due to resource constraints. The aim is for an appointment at this clinic to be within 4 weeks of surgery. A specialist urology preadmission nurse coordinates in the clinic with a goal of minimising cancellations and facilitating early discharge. At the clinic, patients are seen by a consultant anaesthetist, the nurse specialist and by a member of the surgical team. The anaesthetist who sees the patient in the preadmission clinic is usually not the anaesthetist who is due to undertake the operative procedure. Patients undergoing elective surgery are routinely admitted on the day of surgery Elective surgery was undertaken in a morning session (0830-1230), an afternoon session (1330-1730) or an all-day session (0830-1630). Elective surgery is not usually allowed to run over these times due to staffing resources. Acute surgery took place whenever necessary although efforts were made to defer operations to working-hours where not medically contra-indicated. The reasons for cancellation were divided into 5 groups as outlined in Table 1. These were derived from a previously published system that allows for review of the reasons as well as highlights potential modifications that may minimise their occurrence1. Table 1. Standardised cancellation reasons and codes by category Source: Reprinted courtesy of: Argo JL, Vick CC, Graham LA, Itani KM, Bishop MJ, Hawn MT. Elective surgical case cancellation in the Veterans Health Administration system: identifying areas for improvement. The American Journal of Surgery 2009;198(5):600-6. Results Over the almost 3-year period studied, 4303 operations were performed by the Urology department and 180 (4.2%) operations were cancelled. Both figures include elective and emergency surgery. A breakdown of the reasons for cancellation is presented in Table 2. Table 2 Patient cancellations by code Patient factors included 17 cases in which patients either did not adhere to, or were given wrong, instructions e.g. regarding dietary restrictions. Cancellations due to work-up factors (failed preadmission) included 7 patients who remained on anticoagulants or 15 patients whose INR remained high despite them stopping their anticoagulants as advised. 33 patients had a change in their medical status between being booked and their date for surgery. In 12 of these cases the proposed surgery was no longer indicated (10 of them being in patients whose ureteric calculi had passed spontaneously). 21 other patients had their surgery cancelled because of an acute medical illness between the dates of their clinic visit and planned operation. The majority of these illnesses were cardiac or respiratory in nature. From a facility point of view, the non-availability of beds (in 12 cases) was due either to hospital gridlock from winter medical admissions or to the non-availability of pre-requested ICU beds. The largest sub-group of cancellations (43) was due to operating theatre over-runs. We were unable to determine in each case if this was due to prolonged anaesthetic time, prolonged surgical time, more complicated surgery than was anticipated or an over-booked theatre list. 12 patients were cancelled because of an error in scheduling. These were attributable to poor communication or a lack of confirmation between the Urology department administration and the patients involved. Discussion The aim of this study was to identify preventable causes for surgery being cancelled. 4.2% of all operations carried out by the Department were cancelled during the study period. This is equivalent to approximately 60 lost operating lists. Data available in the literature suggests that this figure is low for a tertiary, teaching hospital.1-4 Other studies have reported cancellation rates ranging from 5-13%. We believe this low cancellation rate can be attributed to regular documentation of cancellations at our weekly audit meeting and a departmental goal to prevent such events. When the cancelled cases were assigned reasons according to the ones used in the Veterans Health Administration system, 34 (18.9%) cases were cancelled because of patient factors, 66 (36.7%) because of work-up factors, 70 (38.9%) because of facility factors, 9 (5%) because of surgeon factors and 1 (0.6%) for a miscellaneous reason. In their retrospective analysis of 329,784 cases spread over 9 specialities, patient factors was the most common reason for elective surgical cancellations (35%) and anaesthesia factors was the least common (1%).1 These percentages were similar to our own. A preadmission clinic visit has been shown to reduce operative cancellations.3,5,6 We aim to maximise the number of patients accessing this service in our facility. A standardised preadmission protocol is being developed which may eliminate many of the problems we identified. Although it is accepted that the practicalities of offering all patients a preadmission clinic appointment are intricate, a process that includes an assessment at clinic where indicated but otherwise consists of (at least) verbal communication between hospital-staff and patient prior to surgery is feasible. A nurse-based preadmission model has been shown to be efficient, in particular for ruling out patients who do not need a pre-op anaesthetic assessment5. Streamlining patients thus may mean better utilisation of limited medical and anaesthetic resources Other measures to reduce the rate of surgical cancellations may include an INR check on the day prior to surgery for all patients on warfarin, preoperative anaesthetic assessments done by the anaesthetist assigned to the operation list and a diligent system of requesting and then checking the results of preoperative investigations. Surgical over-runs were the commonest reason for cancellations although we have not identified the specific causes for this in the present study. We plan to add 4 sub-headings to any future audit to determine if an over-run is patient related (more complex surgery than anticipated), surgeon related, anaesthetist related or due to an overbooked list. This will assist in further management of this group. Acute illnesses that rendered an elective patient more at risk from surgery accounted for a large group of cancellations. Currently patients who fall ill between preadmission and surgery are not obligated to inform the hospital of this. A request for immediate notification if a patient has an acute illness preoperatively would seem logical. This could be initiated by the specialist nurse at the preadmission clinic. The main difficulty encountered in this study is one that universally applies to any retrospective analysis - a lack of accurate information. Indeed in some instances, even if all the data was available, reasons for cancellation could feasibly be multi-factorial. There may also have been bias in assigning a reason to operations that were cancelled. A further possible weakness is the fact that information regarding cancellations was gleaned from the minutes of the department's audit meetings. Although unlikely, it is possible that some cancellations were not taken into account due to inaccurate documentation. Conclusion 4.2% of all patients booked had their surgery cancelled over the study period. A proportion of these were avoidable. We aim to reduce this rate by more effectively utilising the preadmission clinic, requesting patient information on inter-current illnesses between preadmission and surgery and defining more clearly the reasons for theatre over-runs in any future, prospective audit.