What is 'global surgery'? Defining the multidisciplinary interface between surgery, anaesthesia and public health.

'Global surgery' is the term adopted to describe a rapidly developing multidisciplinary field aiming to provide improved and equitable surgical care across international health systems. Sitting at the interface between numerous clinical and non-clinical specialisms, it encompasses multiple aspects that surround the treatment of surgical disease and its equitable provision across health systems globally. From defining the role of, and need for, optimal surgical care through to identifying barriers and implementing improvement, global surgery has an expansive remit. Advocacy, education, research and clinical components can all involve surgeons, anaesthetists, nurses and allied healthcare professionals working together with non-clinicians, including policy makers, epidemiologists and economists. Long neglected as a topic within the global and public health arenas, an increasing awareness of the extreme disparities internationally has driven greater engagement. Not necessarily restricted to specific diseases, populations or geographical regions, these disparities have led to a particular focus on surgical care in low-income and middle-income countries with the greatest burden and needs. This review considers the major factors defining the interface between surgery, anaesthesia and public health in these settings.