Background: Despite being implemented for over a decade, literature describing how the surgical safety checklist (SSC) is completed by operating room (OR) teams and how this relates to its effectiveness is scarce. This systematic review aimed to: (1) quantify how many studies reported SSC completion versus described how the SSC was completed; (2) evaluate the impact of the SSC on provider outcomes (C ommunication, case U nderstanding, S afety C ulture, CUSC), patient outcomes (complications, mortality rates) and moderators of these relationships.

Methods: A systematic literature search was conducted using Medline, CINAHL, Embase, PsycINFO, PubMed, Scopus and Web of Science on 10 January 2020. We included providers who treat human patients and completed any type of SSC in any OR or simulation centre. Statistical directional findings were extracted for provider and patient outcomes and key factors (eg, attentiveness) were used to determine moderating effects.

Results: 300 studies were included in the analysis comprising over 7 302 674 operations and 2 480 748 providers and patients. Thirty-eight per cent of studies provided at least some description of how the SSC was completed. Of the studies that described SSC completion, a clearer positive relationship was observed concerning the SSC's influence on provider outcomes (CUSC) compared with patient outcomes (complications and mortality), as well as related moderators.

Conclusion: There is a scarcity of research that examines how the SSC is completed and how this influences safety outcomes. Examining how a checklist is completed is critical for understanding why the checklist is successful in some instances and not others.