The Diversity of Research Participants in Randomized Controlled Trials and Observational Studies Conducted by the Canadian Critical Care Trials Group.

ABSTRACT

RATIONALE Women, older individuals, and racial and ethnic minority groups are often underrepresented in research studies. OBJECTIVES: We evaluated the demographics and diversity of participants enrolled in randomized trials (RCTs) and observational studies published by investigators in association with the Canadian Critical Care Trials Group (CCCTG). METHODS: Quantitative content analysis of peer reviewed RCTs and observational studies from December 1994 to December 2022. For each publication, we extracted participant demographic variables, including sex/gender, age, race or ethnicity, sexual orientation, pregnancy status, language proficiency, income/financial status, housing, education, disability, and geography. RESULTS: 120 publications (28 RCTs, 92 observational studies) enrolled 211,144 participants. Most (107/120, 89.2%) were multicenter studies, and 70% (84/120) were conducted exclusively in Canadian centers; 77.5% (93/120) studies enrolled adult participants, and 19.2% (23/120) enrolled pediatric participants. All studies reported participant mean or median age, 118 (98.3%) reported binary sex or gender, and 9 (7.5%) reported race or ethnicity. No justification was provided in 35 studies which listed pregnancy as an exclusion. There was infrequent reporting of housing (N=4), employment (N=2), income (N=2), and education (N=1). No studies reported language proficiency, sexual orientation, disability or geography of participants. Of the studies reporting gender, women/girls comprised 42.3% participants (range 8.9 to 67.7%). Within 9 studies reporting race or ethnicity of 2950 participants, 59.7% were white, 8% South Asian, 7% Indigenous, 3% Asian, 1% Black, 14% unknown, and 6% 'Other'. CONCLUSIONS: Research publications from the CCCTG infrequently report important participant demographics, and diversity of research participants is disproportionate compared to Canadian societal demographics.