Evaluating minority recruitment into clinical studies: how good are the data?

There has been much publicized concern about difficulty with minority recruitment into research studies, particularly since minority inclusion in randomized clinical trials was mandated by the 1993 National Institutes of Health Revitalization Act. We reviewed recruitment data in published reports from clinical studies to assess the actual degree of success in recruiting minorities versus whites and to identify barriers to recruitment.

We abstracted articles published between September 1993 and February 1995 that reported detailed results of participant recruitment for studies conducted in the United States.

Of 65 articles meeting our eligibility criteria (median sample size, 1323), only one (1.5%) reported the racial/ethnic composition of potential study participants. Only two articles (3.1%) provided information about the racial/ethnic composition of eligible subjects, and only one (1.5%) provided information about the racial/ethnic composition of refusing subjects. For enrolled subjects, race/ethnicity was less likely to be reported (58.5%) than were age (90.8%) or gender (80.0%).

The published literature currently contains insubstantial data to either refute or prove that there are differential recruitment rates among minorities as compared with whites. Changes in reporting will be needed in order to track progress in this area.