Bringing intersectional identities into quantitative research

The idea that a person’s social standing affects their access to healthcare is not new. Most medical research divides group outcomes by race, gender and, often, socioeconomic status. When relevant, categories such as native language or country of origin might also be included.


The increasingly influential theory of intersectionality suggests that those categories need an update. Intersectionality proposes that a person’s multiple social positions are interconnected, mutually constitutive, and, together, influence their access to social goods, such as quality health care.


The claim’s common-sense appeal has led some population health researchers to start looking for statistical models that can better reflect that complexity. Paul Wesson, PhD, and Alice Guan, MPH, are contributing to that search. In a recent paper, they identified more than two dozen methods in eight categories of quantitative methods used in health research published before 2020 that grappled with intersectional social categories. After reading 153 papers where these methods were used, Guan, Wesson and their co-authors flagged the type of research question in which each is most aptly used and identified the strengths and weaknesses of each method.


“We identified 28 analytic approaches that investigators could use, which all come with strengths and limitations,” Guan said. “There is no consensus or perfect method.”


The project originated with Wesson’s work on Christina Mangurian’s R01-funded research on health disparities among those with mental illness. Mental illness is a useful test case for intersectionality, since it imposes barriers to health and healthcare for people in all of the conventional race, class and gender categories, but likely to varying degrees. Wesson and Manguarian decided they would survey methods being used to explore intersectionality and ultimately choose one to use in the research Mangurian leads.


After Guan, a PhD candidate, reached out to Wesson about working with him, she also became interested in the project. She is first author of the current paper, which represents the first phase of the work Wesson and Mangurian charted out. Mangurian is also an author on the paper.


One question seems to bear on the heart of the project: Can a cultural theory, with its roots in legal scholarship, be translated into quantitative methods?


Guan and Wesson noted that some of the research methods indeed seemed at odds with the theory of intersectionality, which insists on social “processes that relate to each other and can’t be teased apart,” as Wesson put it. For instance, decomposition analyses claim to suss out what share of a given disparity is attributable to which social identity.


The paper notes that fewer than half of the studies identified even mentioned the concept of social power or inequality, essentially diluting the intent of intersectionality theory to expose and address structural bias.


“[M]ost of the studies in this review focused on social identity factors, rather than intersecting social structures and power relations, which can lead to attention being shifted away from structural factors in favor of individual-level interventions,” the paper notes. “[I]f the intention of intersectionality work is to advance social justice and equity, it is critical for researchers to focus on modifiable social processes.”


While Wesson is committed to the principles of intersectionality for his own research, he recognizes that not every investigation aims to measure and fix upstream challenges to health. Those that aren’t might be clearer about their aims by avoiding reference to intersectionality, and those that are now have a stronger body of evidence to rely on when devising study methods.


“Using these methods doesn’t make the work intersectional,” Wesson cautioned. “We’re challenging the researchers to think critically about their research question – what are the systems they’re trying to study, and are they focused on systems of power, versus the multiple identities which we all have?”