INTRODUCTION: Racial and ethnic minorities are frequently under-represented in biomedical research in the United States (US), and the under-representation is amplified in clinical trials in patients with rare diseases. The REthinking MeAsures of DivErsity (REMADE) study was conducted to develop and test a set of questions that may more accurately capture the diversity of patients via socioeconomic, cultural, and ethnic parameters. METHODS: A web-based survey was developed to assess race, ethnicity/culture, socioeconomic status, disability/mobility, and transportation issues. The survey responses included 5 racial categories as well as 17 cultures, heritages, and/or ethnicities and were multiselect. The survey was tested in US adults from under-represented populations. Survey results were compared with data collected with a pre-survey intake form (PSIF) that utilized historical categories for race and ethnicity. RESULTS: Of 219 total survey respondents, 59.8% (131/219) were assigned female sex at birth and 51.1% (112/219) were aged ≥ 18 to <
30 years. Respondents reported being predominantly Black [77.3% [163/211)] or white [19.0% (40/211)] in the PSIF. When respondents were allowed to assign percentages across multiple categories in the survey, only 34.2% (75/219) and 10.5% (23/219) identified as 100% Black or white, respectively. As with race, the REMADE ethnicity/cultural categories revealed greater diversity in the respondent population. CONCLUSIONS: The REMADE survey results suggest that race and cultural identity are more multidimensional than historical questions/categories were able to capture. These insights, along with those generated on socioeconomic, disability, and transportation issues, will guide initiatives to support fair and equitable representation in clinical trials.