''In 1935, the U.S. Army Air Corps held a flight competition for airplane manufacturers vying to build its next-generation long-range bomber. In early evaluations, the Boeing plane had trounced other designs. The flight "competition," was regarded as a mere formality. With the most technically gifted test pilot in the army on board, the plane roared down the tarmac, lifted off smoothly, and climbed sharply to three hundred feet. Then it stalled, turned on one wing, and crashed in a fiery explosion. Two of the five crew members died, including the pilot. An investigation revealed that nothing mechanical had gone wrong. The pilot had forgotten to release the new locking mechanism on the elevator and rudder controls. A few months later, army pilots were convinced the plane could fly and invented something that would be used on the few planes that had been purchased... A checklist, with step-by-step checks for takeoff, flight, landing, and taxiing. With the checklist in hand, the pilots went on to fly the model (B-17) a total of 1.8 million miles through several conflicts without one accident.''
This episode has been heralded as the key milestone in the birth of the checklist.
The delivery of healthcare is complex and hence riddled with the potential for errors due to human factors, system failures and, more commonly, a combination of the two . Fortunately, many of these errors do not result in harm, but some do, often as a result of a multiplicity of minor errors co-aligning and resulting in a more serious event that results in patient harm . The proliferation of epidemiological and qualitative research into medical errors has contributed to improvements in our understanding of the root causes of many of these errors . Clinical outcomes, morbidity and mortality are the product of both technical and non-technical skill. Indeed analysis of error and morbidity suggest that technical failures account for only a small proportion of these. Healthcare systems are now recognized to be a series of complex interrelated Microsystems  where clinicians, patients and patterns of practice interact to determine the outcome . It is clear that substantial aspects of clinical practice are now too complex for groups of healthcare professionals to carry out reliably from memory alone. Surgery is one such example where clinicians are faced with high levels of uncertainty in their daily work, which may impact on the quality and safety of care patients receive . This understanding means that it is important for professionals (and their respective bodies) to identify and implement strategies that reduce the risk of iatrogenic harm while at the same time ensuring that optimum outcomes are most likely.
In the UK, most people will have surgery at some point in their life. Approximately 4.2 million surgical operations are carried out every year in England alone. That equates to one operation for every 12 people per year . Surgery has been categorised as a very unsafe undertaking with a rate of fatal adverse events (catastrophic events per exposure) of 1 per 10,000 surgical procedures. In industrial countries, major complications occur in 3-16% of inpatient surgical procedures and permanent disability or death rates are 0.4-0.8% . In trauma surgery, the rate of serious complications is substantially higher at an estimated 1 per 100 surgical exposures. By contrast, in civil aviation, railway transport and nuclear power the rate of death is less than 1 per million exposures .
Whilst surgical training and practice has focused on technical skills and technological advances there has been little recognition of the benefits of non-technical skills (human factors). Most of the errors that occur during surgery can be attributed to failures in these non-technical skills such as situation awareness, decision making, communication and teamwork and leadership. Other high-risk industries such as aviation and petroleum have made great progress in managing these challenges and have reduced harmful events by several orders of magnitude. They have achieved this by accepting that humans working in complex systems inevitably make errors and have provided opportunities to learn and improve performance. This insight has led to a focus on building systems that reliably deliver what is required and that identify errors that occur with built in mitigation steps that prevent errors causing harm. Central to the success of such initiatives has been an increased appreciation of the role of human factors, the value of teamwork and the principles of reliable system design. Specifically they have built formal mechanisms of communication, trained in non-technical skills and developed checklists .
In January 2007, the World Health Organization (WHO) began a programme aimed at improving the safety of surgical care globally. This initiative - Safe Surgery Saves Lives - identified minimum standards of surgical care that can be universally applied across countries and settings . A core set of safety checks was developed in the form of a WHO Surgical Safety Checklist that can be used in any surgical setting and operating theatre environment. Each step in the checklist is simple, widely applicable, measurable, and has been shown to be associated with a reduced risk of death and major complications in a range of clinical settings. The instrument suggests three phases: Sign-in, Time-out and Sign-out. The "Sign-in" is done prior to induction of anaesthesia and includes confirmation of patient identification, consent and site-marking as well as checks for allergies, assessment of difficult airways and anticipated blood loss. "Time-out" occurs just prior to skin incision and serves to confirm the patient, site, procedure and position, the application of the surgical site infection bundle, the use of venous thromboembolism prophylaxis, the presence of the correct imaging, equipment sterility and the anticipation of any critical steps. Prior to the removal of the drapes, the "Sign-out" confirms the procedure performed and the instrument and swab counts as well as plans for post-operative management. These questions are a final check. They are intended to be usually a redundant step in the process identifying the few occasions when all other processes have failed to ensure the patient receives everything intended. This and the simple effect of knowing they are to be asked significantly improve the reliability of the clinical processes and may reduce complications by up to 50% .
The NPSA has instituted the NRLS database of patient safety incidents (PSIs) . Running since 2003, this database is now the largest of its kind in the world, already having received over four million reports of events that caused or had the potential to cause harm . Incident reporting does not reveal the true incidence or prevalence of errors, but the volume or reports gathered can provide important insights into the frequency and causes of errors, and offer opportunities to identify possible ameliorative responses . Reports continue to accrue at an accelerating rate, with the database currently receiving approximately a quarter of a million reports per quarter. Data from 2008 reveal that of these, 152,017 incidents (15.5%) related to surgery and of these 32.4% (49,254 incidents) related to orthopaedics and trauma .
Wrong-site surgery represents a devastating event for all parties concerned. Data from the National Health Service Litigation Authority (NHSLA) in 2006 reveal that the cost of settling wrong-site surgery claims was over £1 million pounds in England alone . NHSLA data also reveal that trauma and orthopaedics had the highest number of claims with 29.8% of the total compared with the next specialty, dentistry at 16.8% . For example, an analysis of NHSLA data combined with the NHS records for the total number of surgical procedures carried out in the period 2006 to 2007 confirms that orthopaedic surgery has the highest rates of wrong-site surgery .
In the NRLS wrong site surgery is classified as any event in which surgery is performed with the 'wrong patient', 'wrong site prosthesis', 'wrong side surgery', 'wrong side marked on patient', 'wrong side block', 'wrong side marked on theatre list' and 'wrong side marked on consent form'. The aim of this study was to assess how many PSIs related to wrong site surgery occurred in orthopaedics and of those how many could have been prevented by the use of the WHO surgical checklist.