text: Physician leaders cross boundary use of social media what are the implications in the current COVID 19 environment The purpose of this study is to better understand social media SM factors that physician leaders need to consider as they adapt their cross boundary practices to engage with colleagues and patients Firstly this study explores why SM is being used by physicians to cross horizontal physician to physician and stakeholder physician to patient boundaries prior to COVID 19 Secondly based on the studies reviewed this study provides insights on the practical SM implications for physician leaders working in the COVID 19 environment to actively enhance their practices reduce public confusion and improve patient care thus informing health care practices A systematic literature review was used to conduct a structured transparent overview of peer reviewed articles that describe physicians use of cross boundary SM across several disciplines e g health information science As a baseline assessment prior to COVID 19 the review synthesized 47 articles identified and selected from six databases and Novanet This study used NVivo 12 to thematical code the articles leading to the emergence of four broad factors that influence SM use A key reason noted in the literature for physicians use of SM to cross horizontal boundaries is to share knowledge Regarding stakeholder boundaries the most cited reasons are to improve patients health and encourage behavioural changes Insights garnered on the practical SM implications include the need for physicians to be stronger leaders in presenting trustworthy and consistent facts about health information to the public and fellow peers As role models for the effective use of SM tools physician leaders can mentor and coach their colleagues and counterparts As this was a literature review the authors did not collect primary data to further explore this rapidly changing and dynamic SM world Next steps could include a survey to determine firstly how physicians currently use SM in this COVID 19 environment and secondly how they could leverage it for their work Findings from this survey will help us better understand the role of physician leaders as health care influencers and how they could better create trust and inform the Canadian public in the health information that is being conveyed Physician leaders can play a key role in positively influencing institutional support for ethical and safe SM use and engagement practices Physicians need to participate in developing regulations and guidelines that are fundamentally to physician leaders SM use Central to this research would be the need to understand how physicians cross boundary practices have changed during and potentially post COVID 19 Physician leaders also need to monitor information sources for credibility and ensure that these sources are protected As role models for the effective use of SM tools physician leaders can mentor and coach their colleagues and counterparts in this area Although there have been studies of how physicians use SM fewer studies explore why physician leaders cross boundaries horizontal and stakeholder using SM Important insights are gained in physician leaders practical use of SM Key themes that emerged included organizational and individual information professional and regulations and guideline factors These factors strengthen physician leaders understanding of areas of foci to enhance their cross boundary interactions There is an urgency to study the complexity of SM and the effectiveness of regulations and guidelines for physicians who are being required at an accelerated rate to strengthen and increase their cross boundary practices 