For example, since 2001, researchers funded by the US National Institutes of Health have been required to categorize study participants into five racial or ethnic categories. "State-sanctioned but ill-defined categories of race have entered medical research and practice," say the authors, "with the admirable intent of ensuring full racial and gender inclusion in clinical trials, but with unanticipated consequences for health outcomes."
One of these consequences, say the authors, is that clinicians and researchers may use these categories, which are social and historical in nature, as "biological or attributive categories appropriate for individual treatment." In other words, there is a risk that race becomes inappropriately used as a proxy for biological difference.
"Race remains a social characteristic of populations," say Fausto-Sterling and colleagues, and it is inappropriate to use it as a central diagnostic tool for an individual patient."
In a related perspective article, George Ellison (St George's, University of London, UK) and colleagues say there is a lack of consensus about what race and ethnicity mean and how these should be operationalised. Yet even though researchers themselves often recognise that racial and ethnic categories are imprecise markers of genotypic and socio-cultural determinants of variation in health, say the authors, "they have adopted an essentially pragmatic response to the perceived need for standardised, salient, and politically sensitive classifications."
Finally, an editorial by the PLoS Medicine editors discusses what role medical journals can play in ensuring that race, ethnicity, and other human variables are accurately described. "Editors should insist," they say, "that authors of studies based on different human categories should make their methods of categorizing human populations transparent, justify their study design, and control for confounding variables."