Defining Intensivists: A Retrospective Analysis of the Published Studies in the United States, 2010-2020

The Society of Critical Care Medicine last published an intensivist definition in 1992. Subsequently, there have been many publications relating to intensivists. Our purpose is to assess how contemporary studies define intensivist physicians. Systematic search of PubMed, Embase, and Web of Science (2010-2020) for publication titles with the terms intensivist, and critical care or intensive care physician, specialist, or consultant. We included studies focusing on adult U.S. intensivists and excluded non-data-driven reports, non-U.S. publications, and pediatric or neonatal ICU reports. We aggregated the study title intensivist nomenclatures and parsed Introduction and Method sections to discern the text used to define intensivists. Fourteen parameters were found and grouped into five definitional categories: A) No definition, B) Background training and certification, C) Works in ICU, D) Staffing, and E) Database related. Each study was re-evaluated against these parameters and grouped into three definitional classes (single, multiple, or no definition). The prevalence of each parameter is compared between groups using Fisher exact test. U.S. adult ICUs and databases. None. Of 657 studies, 105 (16%) met inclusion criteria. Within the study titles, 17 phrases were used to describe an intensivist; these were categorized as intensivist in 61 titles (58%), specialty intensivist in 30 titles (29%), and ICU/critical care physician in 14 titles (13%). Thirty-one studies (30%) used a single parameter (B-E) as their definition, 63 studies (60%) used more than one parameter (B-E) as their definition, and 11 studies (10%) had no definition (A). The most common parameter "Works in ICU" (C) in 52 studies (50%) was more likely to be used in conjunction with other parameters rather than as a standalone parameter (multiple parameters vs single-parameter studies; 73% vs 17%; p < 0.0001). There was no consistency of intensivist nomenclature or definitions in contemporary adult intensivist studies in the United States.