Linguistic Barriers in Clinical Research: Examining the Underrepresentation of Non-English Speakers in U.S. Clinical Studies from 2015–2024

The underrepresentation of non-English-speaking patients in clinical studies in the U.S. poses significant challenges to the generalizability and equity of medical research. This study systematically analyzes inclusion and exclusion criteria in clinical studies to assess trends in language-based participant exclusion over the past decade. Using data from studies registered on ClinicalTrials.gov from 2015-2024, the prevalence of language restrictions and their implications for healthcare disparities are examined. Findings indicate that the proportion of clinical studies that explicitly exclude all non-English speakers has increased over the past decade. The implications of these findings underscore the need for policy interventions, methodological adaptations to enhance linguistic inclusivity in clinical research, and further investigation into the underlying causes of this trend. Addressing these disparities is critical to ensuring that medical research benefits diverse populations and contributes to equitable healthcare outcomes. This study advocates for the standardization of multilingual inclusion strategies and enhanced regulatory oversight to mitigate linguistic barriers in clinical research.