• healthcare quality improvement
• health policy
• health services research

Patients are more likely to experience preventable harm during perioperative care than in any other type of healthcare encounter.1 2 For several decades, a hallmark of surgical quality and safety has been the use of checklists to prevent errors (eg, wrong site surgery) and assure that key tasks have been or will be performed. The most widely used approach globally is the Surgical Safety Checklist (SSC) recommended by the WHO.3 It is divided into preinduction (or sign in, consisting of seven items performed by anaesthesia and nursing), preincision (timeout, 10 items performed by the entire team) and postsurgery (sign out, five items by the entire team).4 5 Most hospitals in the developed world perform the SSC or an equivalent timeout prior to surgical incision. However, preinduction briefings, and postcase debriefings in particular, are much less commonly performed.6 7

There are widely disseminated arguments recommending the use of checklists in healthcare8 but also recognised limitations.9 Checklist-based preincision timeouts appear to improve surgical outcomes in many settings,4 5 yet, in other hospitals, the introduction of the SSC failed to improve outcomes.10 Like all tools or processes intended to improve safety, ineffective implementation will reduce the desired benefits. For example, there is appreciable evidence showing that surgical teams skip or do not meaningfully respond to timeout checklist items.11 12 Even with a robust implementation, effectiveness can be weakened by contextual factors, failure of leadership or deficient safety culture.

Despite numerous studies, gaps in the evidence to guide optimal checklist use persist. For example, we do not know whether checklist-based timeouts only decrease the occurrence of the undesirable events targeted by the checklist or, as many hypothesise, whether their use also facilitates teamwork and interprofessional communication. Although there is increasing guidance on …