The WHO surgical safety checklist was implemented in 2008. In 2009, Haynes’ et al. published a landmark study which began a growing mountain of evidence to support the use of these checklists [2]. This study prospectively collected data on approximately 4000 patients from a diverse group of eight hospitals worldwide before and after implementation of the SSC. The authors demonstrated reductions in death (1.5–0.8 %, p = 0.003) and inpatient complications (11.0–7.0 %, p < 0.001) with checklist use. Many of the studies that followed have been prospective or retrospective observational studies to evaluate the results of SCC implementation in more specific clinical settings (Table 40.1).

While no prospective randomized control studies have been (or likely will be) done, Gillespie et al. performed a robust meta-analysis including seven prospective cohort studies of 37,339 patients, concluding that SSC’s significantly reduce postoperative complications [4]. Van Klei et al. reported a significant reduction in mortality when checklists were fully completed [16]. Lastly, in an attempt to remove confounders, Haugen et al. described an elaborate protocol for SSC implementation, finding significant reductions in morbidity and length of stay [8]. Collectively, these studies indicate that implementation of surgical safety checklists likely improves post-operative outcomes including mortality rates.

However, the benefits above have not been demonstrated in all studies. Several investigators have suggested necessary conditions under which morbidity and mortality can be reduced. Surgical safety checklists are designed primarily to prevent deaths from perioperative errors, which are rare events. Therefore, the intervention of introducing checklists should be with the expectation of population-level benefits, and that a large cohort size will be required to demonstrate effectiveness. Second, some authors have demonstrated effectiveness by examining higher-risk populations (e.g., complicated procedures, unplanned procedures, colorectal operations, and procedures at limited-resource hospitals [3, 5, 9, 10, 12, 15, 17]) or by studying more common or impactful outcomes (e.g., re-operation, infection rates, length of stay [5, 9, 10, 12–18]). Safety culture and attitudes may also play a role in checklists and patient outcome. Haynes et al. updated their original work with a survey of attitudes toward the SSC and found essentially a dose-response curve in which changes in outcomes were directly associated with team perceptions of successful checklist implementation [23]. Fidelity of checklist use and completion has been shown to have a direct correlation with reduction in morbidity [16]. Therefore, the evidence clearly indicates that checklists reduce morbidity and mortality effectively, as long as they are being used as intended.

In addition to preventing morbidity and mortality, other indirect measures of quality have been shown to improve with SSC use (Table 40.2). Standardized perioperative processes of care have been shown to improve outcomes. Performance measures including antibiotic timing, intraoperative hypothermia management, and hypoxemia have all been shown to improve with checklist implementation [5, 9, 17]. As a further indication of SSC success, implementation has improved perceptions of perioperative patient safety and communication among operative teams [17, 23].

The vocal critics who oppose the conception of surgical safety checklists have expressed concerns and negative perceptions in the form of anecdotal evidence, surveys, and opinion papers. Some believe that use of a checklist in the operating room is ineffective, unnecessary, and reduces operating room efficiency [25]. Even though there are studies that have failed to demonstrate effectiveness, the concerns brought forth by these critics have not been objectively validated and in some cases directly refuted. Two cohort studies have shown no difference in operative times before and after SSC implementation [12, 26]. This seems intuitive since the checklist itself takes only a few minutes. Results from our institution indicate that SSC implementation did not affect first-start in room on time performance or same day cancellations [9]. Furthermore, the cost of SSC has been investigated. Semel et al. calculated a cost-savings of $103,829 per year assuming prevention of five major complications during 4000 non-cardiac operations [24]. Therefore, checklists have the added benefit of improving performance of standardized care, perception of patient safety, and communication among team members without adversely affecting operating room efficiency or cost.

From the inception of checklist utilization, barriers to their use have been present (Table 40.3). The most obvious of these is non-use or failure to complete the checklist [6, 27]. However, “checklist mentality” leads to misuse even after a high completion rate is achieved. Several investigators have audited checklists and team behavior, universally finding poor checklist fidelity [16, 37, 39]. This may be a direct result of checkbox fatigue where the process turns from one of patient safety and benefit to one of mundane automatic (or mindless) checking of a box.