CTSI Special Populations: DRAFT Inclusion of Clinical Research Snapshot (in progress)


This Inclusion of Clinical Research Snapshot provides a summary of demographic representation for participants in Duke clinical research studies. The Inclusion of Clinical Research Snapshot presents information from studies as entered into the Duke clinical research management system (OnCore) with any accrual status as of March 25, 2021. We assessed the following demographic variables: age, gender, race, ethnicity, and rurality. Our primary objective is to determine the inclusion of traditionally underrepresented groups in research in Duke clinical trials.


For more information about the data shown, you may download the Technical Appendix via the link immediately below:

Over half of Duke clinical research participants were females (58.5%).   

Gender: (OnCore database, March 2021)



1. Unknown indicates that the participant's data include 'Unknown' as an explicit value 

2. Not Reported indicates the participant's data contain no value in the column for gender

Approximately half of Duke clinical research participants were between the ages of 27 and 64 years of age (52.5%).

Age at Time of Accrual: (OnCore database, March 2021)

  • Ages 65 to 100: 25.4% (n= 72,332)
  • Ages 27 to 64: 52.5% (n= 149,749)
  • Ages 18 to 26: 8.5% (n= 24,275)
  • Ages 5 to 17: 6.2% (n= 17,646)
  • Under 5: 6.5% (n= 18,537)
  • Not Reported: 0.9% (n= 2,635)
  • Outliers: <0.05% (n= 35)


1. Not Reported indicates the data extract contained no value in the column for age

2. Outliers is a category for data in the extract that includes both negative values and values over 100 years of age

Approximately 25-27% of Duke clinical research participants self-identified as minorities.

Race: (OnCore database, March 2021)



Most of Duke clinical research participants were Non-Hispanic compared to Hispanic/Latino (79.3% vs. 4.3%, respectively).

Ethnicity: (OnCore database, March 2021)


The majority (70.8%) of Duke clinical research participants live in non-rural areas while 17.3% live in rural areas.



Rurality was determined by using a file that maps zip codes to 2010 Rural-Urban Commuting Area Codes (RUCA codes).  For a description, refer to https://www.ers.usda.gov/data-products/rural-urban-commuting-area-codes.aspx.2

Zip codes reported in OnCore were grouped using primary RUCA codes into rural and non-rural participant locations. More specifically, a primary RUCA code of 1, 2, or 3 was considered non-rural and codes 4 through 10 as rural.

2The USDA’s (U.S. Department of Agriculture) Economic Research Service publishes a dataset of RUCA codes at https://www.ers.usda.gov/data-products/rural-urban-commuting-area-codes.aspx


Duke Research Participant Age Categories Compared to Benchmarks

Participations by Age Category versus Benchmarks

Please refer to the Technical Appendix for all benchmark sources. 

Race and Ethnicity breakdowns versus Census