The WHO surgical safety checklist: a review.
Abstract: Surgery plays a prominent role in healthcare worldwide. It has been estimated that the rate of fatal events occurring in surgery is about one in ten thousand exposures and up to one million deaths per year. Most errors are caused by failure of non-technical skills. The WHO surgical safety checklist has shown that patient safety could be improved by using a simple and effective method. However, achieving high compliance requires research, training and local adaptation.

KEYWORDS Surgical safety / Surgical checklist / WHO
Article Type: Report
Subject: Safety regulations (Safety and security measures)
Medical errors (Safety and security measures)
Authors: Alnaib, Mustafa
Samaraee, Ahmad Al
Bhattacharya, Vish
Pub Date: 09/01/2012
Publication: Name: Journal of Perioperative Practice Publisher: Association for Perioperative Practice Audience: Academic Format: Magazine/Journal Subject: Health; Health care industry Copyright: COPYRIGHT 2012 Association for Perioperative Practice ISSN: 1750-4589
Issue: Date: Sept, 2012 Source Volume: 22 Source Issue: 9
Topic: Event Code: 260 General services
Accession Number: 309315283
Full Text: Background

The delivery of healthcare is complex, with potential for errors caused by human factors and system failures (Panesar et al 2011). In the twenty first century, patient safety has become an important issue in healthcare management worldwide (Yang et al 2007). Most errors that occur in surgery are caused by failures of non-technical skills such as communication, leadership and teamwork. To increase awareness and understanding of this considerable issue, patient safety is being developed as a medical school curriculum by patient safety scholars in partnership with John Hopkins University (Lancet editorial 2008).

Surgery plays a prominent role in healthcare worldwide with growing attention to quality and safety in the delivery of such care (Haynes et al 2011). The increasing focus on surgical safety appeared with the categorisation of surgery as a very unsafe industry. It has been estimated that 234 million operations are being carried out annually worldwide with a rate of fatal events occurring at 1 per 10,000 exposures, and up to one million deaths per year (Haynes et al 2009).

Trauma surgery alone has a complication rate of 1 in 100 exposures, whereas the rate of death in the aviation, railway and nuclear industries is less than one per million exposures (Emerton et al 2009). In developed countries, the rate of serious complications from surgical procedures ranges from 3 to 16%, and interestingly, around half of these incidents are preventable and avoidable (Lancet editorial 2008, Mahajan 2011, Allard et al 2011).

Evidence from root cause analyses suggests that we do most of the things for most patients most of the time, but not all of the things for all patients all the time (Reid & Clarke 2009) Although the incidence of operating on the wrong patient or wrong site is rare, the consequences are considerably harmful to the patient (Panesar et al 2009). In 2007 a surgical safety checklist was introduced globally through the World Health Organization's Safe Surgery Saves Lives program to reduce complications and deaths associated with surgery (Haynes et al 2009).


This review looked into the historic events and the evidence behind the introduction of the World Health Organization (WHO) checklist in clinical practice, and the evidence following its implementation.


A critical appraisal of the WHO surgical safety checklist publication by Haynes et al was carried out. A literature search was performed to identify the relevant articles according to an agreed search strategy and inclusion criteria. The relevant articles were included in this review.

Search strategy

An electronic search of medical databases including Medline/Pubmed, CINAHL and EMBASE was carried out. The keywords used were: surgical safety, surgical checklist, WHO. To be included in the review identified articles were: clinical studies, editorials or reviews published in English between January 2009 and September 2011. The search resulted in 182 articles which were analysed by the authors. Seventeen of those 182 articles were considered to fulfil the inclusion criteria and were included in this review.


The WHO has been, and is still, considering safe surgery as a significant public health concern in the developing and developed countries (Schlack & Boermeester 2010). In 2007, the WHO initiated a programme called Safe Surgery Saves Lives which was aimed at improving safety in surgery on a global scale. The surgical safety checklist was created in an attempt to address this concern (Haynes et al 2009, Panesar et al 2011).

The origin of safety checklists perhaps lies in the aviation industry (Emerton et al 2009). In an American Army flight competition held in 1935, a highly technically gifted pilot flew a Boeing plane. The plane lifted off and climbed to three hundred feet, stalled, turned on one wing, and crashed in a fiery explosion. The pilot and another member of the crew died. An investigation revealed no mechanical errors, but the pilot had forgotten to release the new locking mechanism. A few months later, army pilots invented a checklist with step-by-step checks for takeoff, flight, landing, and taxiing. With the checklist in hand, the pilots went on to fly a total of 1.8 million miles through several conflicts without one accident reported (Gawande 2007).

This incident has been considered as the key milestone in the development of safety checklists (Emerton et al 2009). Since then the checklists, along with briefing and debriefing sessions, have become instrumental in enhancing the safety culture (Mahajan 2011). The key elements of safety checklists are certainly not new to surgeons or anaesthetists, as information is routinely checked and documented. For example, orthopaedic surgeons in North America have been encouraged to prevent wrong-site surgery since 1997 following the recommendations by the American Academy of Orthopaedic Surgeons and the Canadian Orthopaedic Association (Yang et al 2007). The Royal College of Surgeons of England recognised the obligation of surgeons to conduct preoperative briefing as part of a responsibility to patient safety (Allard et al 2011). However, the medical profession in general has been criticised as being slow in adopting safety checklists (Mahajan 2011).

The WHO surgical safety checklist

In 2007, a nineteen item checklist was developed by the WHO Safe-Surgery-Saves-Lives group (WHO 2007), and it was introduced in eight countries (Haynes et al 2009). The authors hypothesised that the implementation of a surgical safety checklist together with changes in culture would lead to a reduction in major surgical complications and death rates after surgery in various healthcare settings. Eight hospitals in eight countries with different socioeconomic environments were selected to participate in the implementation of the checklist. Since the publication of the Haynes study, 3900 hospitals in 122 different countries have adopted the use of the checklist, with national level adoption in 25 countries (Conley et al 2011). All UK hospitals implemented the check list in 2010 (Panesar et al 2011).

Data were collected prospectively to determine the baseline status prior to implementation of the checklist, followed by prospective collection of data following the introduction of the checklist. Training was provided to the operating-room staff by the local study group and data collectors.

The checklist consists of three safety checks and junctures: 'Sign in', 'Time out' and 'Sign out'. At these junctures, all operating room team members should stop their activities and pay attention to the check. The patients can also participate in the 'Sign in' phase prior to induction of anaesthesia to check identity and planned procedure (Haynes et al 2009).

* Sign in

Prior to induction of anaesthesia, members of the team orally confirm that the patient has verified his or her identity, the surgical site and procedure, and given consent. It also confirms whether the surgical site is marked or that site marking is not applicable. In addition, it confirms the pulse oximeter is on the patient and functioning and whether all members of the team are aware of whether the patient has a known allergy. The patient's airway and risk of aspiration is evaluated and appropriate equipment and assistance are available. If there is a risk of blood loss of at least 500 ml (or 7 ml/kg of body weight in children), appropriate access and fluids are made available (Haynes et al 2009).

* Time out

Prior to skin incision, the entire team (nurses, surgeons, anaesthesia professionals and any others participating in the care of the patient) orally confirms that all team members have been introduced by name and role, the patient's identity, surgical site, and procedure. The surgeon reviews the anticipated and unexpected critical events, operative duration, and anticipated blood loss. Anaesthesia staff review concerns specific to the patient. Nursing staff review confirmation of sterility, equipment availability, and other concerns. Prophylactic antibiotics are administered within 60 minutes of the incision or a clarification is made that antibiotics are not indicated. All essential imaging results for the correct patient are checked if displayed in the operating room (Haynes et al 2009).

* Sign out

Before the patient leaves the operating room, the nurse reviews items aloud with the team, name of the procedure as recorded, and the needle, sponge, and instrument counts. The nurse also confirms the specimen (if any) is correctly labelled, including with the patient's name and whether there are any issues with equipment to be addressed. The surgeon, nurse, and anaesthesia professional review aloud the key concerns for the recovery and care of the patient (Haynes et al 2009).

Critical appraisal

The study asks a clear and focussed question about whether a surgical safety checklist reduces the morbidity and mortality in a global population. The authors claim that there was no statistically significant difference between the two groups, but this only applies according to the study to age, sex, urgency of case, whether it was an outpatient procedure or not and whether general anaesthesia was used. There is no evidence from the data presented as to whether the American Society of Anaesthesiologists (ASA) grade of the patients, the surgical specialty and/or patient co-morbidities were taken into consideration when comparing both groups. This could have potentially influenced the results of the study with regards to mortality if there was a statistically significant difference in the ASA grade of the patients or the patients' co-morbidities. A similar effect could have been observed when adjusting for surgical speciality, for example: orthopaedics, where the appropriate use of antibiotics could influence the rate of infection (Haynes et al 2009).

A sample size was calculated with high statistical power (80%), although this was not achieved in three sites even after the extension of the study period, with no explanation on the implication of this on the statistical power of the study. According to the study, local ethics committees were approached to approve the study, who waived the requirement to obtain patient consent. The only two exclusion criteria mentioned in the published study were if patients were under the age of 16 years and/or if patients were undergoing cardiac surgery.

The outcomes of the study were clearly defined prior to the study and had been fully followed up for the participating patients in each site. The results were blinded to the primary investigators at the local hospital by the data collectors.

The study showed that complication rates reduced from 11% to 7% (p<0.001), and mortality rate was reduced from 1.5% to 0.8% (p=0.003) with use of the checklist. The impact on mortality was predominantly observed in data from the developing countries. In addition, the largest reduction in surgical site infection (from 20.5% to 3.6%) was observed in one of the resource-poor hospitals who had no policy of routine antibiotic prophylaxis within 60 minutes prior to the implementation of the checklist (Senior 2009). In contrast, there was no significant difference in reduction of the mortality rate in hospitals of high income countries, which makes it difficult to draw conclusions on the effect on implementing the checklist in the UK (Vijayasekar & Steel 2009).

The introduction of the WHO surgical safety checklist is an important step in introducing safe culture in surgery, and medicine in general (Schlack & Boermeester 2010), with a unique opportunity for clinicians to provide leadership (Mahajan 2011). It is equally important that systems are in place to detect errors before they escalate and that there is defensive capacity when events develop further (Panesar et al 2011).

This study has shown that the core set of the safety checks in the WHO surgical safety checklist can be applied to any surgical setting (Panesar et al 2011). It has also provided good evidence that routine preoperative time-out procedures reduce postoperative mortality and complications (Schlack & Boermeester 2010). The importance of teamwork has been emphasised in this study, which could have directly or indirectly contributed to the good outcomes. Taylor et al (2010) acknowledged that communication and conversation between the team members, not the exact documentation, create a healthy culture. Moreover, communication failures result in errors in omission and commission, and it is rational that team members should be communicating respectfully and efficiently.

The adoption of the WHO surgical safety checklist has been met with mixed reactions (Mahajan 2011). Despite the robust and strong evidence provided by the study, it could not identify the exact mechanisms by which these results were achieved (Schlack & Boermeester 2010). This was acknowledged by Haynes et al (2011). The reasons were considered to be multifactorial involving system changes, team behaviour factors and communication. Interpretation of the study results should be approached carefully, as extrapolation of the results in a total population of around 8000 to a large world surgical population of 234 million is risky (Taylor et al 2010).

Mahajan has highlighted a number of barriers to the implementation of the WHO surgical safety checklist (Mahajan 2011). Bringing members of the team face to face together could potentially cause embarrassment especially in operating theatres where this procedure is an entirely new concept and it may take time for staff to be familiarised with the routine. Hierarchy of staff could also be a barrier in implementation, and the checklist is more likely to be completed when the surgeons and anaesthetists are supportive or when the nurses were confident. Also, it is often difficult to have a surgeon present during the sign in and sign out phases, when surgeons are either seeing other patients or writing operation notes.

A safety checklist should be simple, as evidence from the nuclear industry suggests that there may be higher chance in overlooking items when the list grows (Mahajan 2011). Even with simple checklists, adoption would efficiently occur after gaining the support of staff, as efforts to push the implementation could potentially lead to the process becoming a tick-box exercise without realisation of its benefits. This view has been shared by other authors who considered that the addition of a new checklist to the existing burden of tick-box lists without appropriate training could lead to tick-box fatigue, and at worst could turn out to be counter-productive (Vijayasekar & Steele 2009). Panesar et al (2010) have also suggested that incorrect use of checklists can be hazardous to patients, and could lead to prolonged theatre lists.

Some of above barriers have been addressed by Conley et al (2011) who suggested that sustaining success in implementation of the surgical safety checklist is through ongoing observation, with emphasis on reading the checklist rather than relying on memory They also concluded that effectiveness of implementation relies on the ability to explain why and how to use the checklist. Vijayasekar and Steele (2009) concluded that no studies have yet examined team composition or experience and its impact on outcomes, and it would be difficult to draw conclusions on the mechanism of achieving such results with the introduction of a safety checklist. They have also concluded that without robust data collection systems set up to study the implementation of this checklist, the clinical effectiveness lacks the backing of sound clinical knowledge.


Patient safety has been and will always be a priority in any healthcare setting. Use of the surgical safety checklist has shown good evidence in reducing mortality and morbidity, and it has been suggested that the list should be adapted to local circumstances due to differences between surgical specialties. A multidisciplinary checklist that covers the whole surgical pathway from admission to discharge is encouraged (Schlack & Boermeester 2011). However, modifying for local use may increase complexity and result in less functionality (Wilson & Walker 2009). To achieve high levels of compliance, vigorous procedures such as legislation are required (Yang et al 2007), in addition to guidance by passionate leadership and execution by committed staff (Taylor et al 2010). It is also reassuring that compliance with checklist completion improves over time with integration into the culture and workflow of the operating room (Avansino et al 2011).

In summary, The WHO surgical safety checklist has shown that patient safety could be improved using a simple, effective and affordable method. However, achieving high compliance and the presence of various implementation barriers requires effort through research, training and local adaptation.

Main messages

* Most errors that occur in surgery are caused by failures of non-technical skills such as communication, leadership and teamwork.

* The WHO surgical safety checklist has shown that patient safety can be improved using a simple, effective and affordable method.

* Achieving high compliance and the presence of various implementation barriers requires effort through research, training and local adaptation.


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by Mustafa Alnaib, Ahmad Al Samaraee, Vish Bhattacharya

Correspondence address: Mr Ahmad Al Samaraee, Speciality Registrar in General Surgery, South Tyneside District Hospital, South Shields, NE34 0PL. Email:

About the authors

Mustafa Alnaib


Orthopaedic Registrar, University Hospital of North Durham

Ahmad Al Samaraee


Speciality Registrar in General Surgery, South Tyneside District Hospital

Vish Bhattacharya


Consultant Surgeon, Queen Elizabeth Hospital, Gateshead

No competing interests declared

Provenance and Peer review: Unsolicited article; Peer reviewed, Accepted for publication May 2012.
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