“I remember thinking, as a young assistant professor, ‘Oh my God, you can actually measure racism?’ recalled Ichiro Kawachi. He was referring to the groundbreaking work two decades ago of his colleague, social epidemiologist Nancy Krieger. “Nancy made visible what was unspeakable, unspoken of, invisible. No one had done this before—they thought it was too sensitive, too difficult. She launched an entire field by saying, ‘If we think this is important, let’s measure it.’”
Krieger’s ecosocial epidemiologic theory of disease distribution—which analyzes how people literally embody their societal and ecological context, thereby producing population rates of disease—has influenced a generation of researchers. Explaining the comparatively high risk of hypertension among African Americans, for example, Krieger wrote in a 1994 paper, “Epidemiology and the Web of Causation: Has Anyone Seen the Spider?”: “A person is not one day African American, another day born low birth weight, another day raised in a home bearing remnants of lead paint, another day subjected to racial discrimination at work (and in a job that does not provide health insurance), and still another day living in a racially segregated neighborhood without a supermarket but with many fast food restaurants. The body does not neatly partition these experiences—all of which may serve to increase risk of uncontrolled hypertension.”
In 1996, Krieger shook up the field with a study suggesting that bearing the brunt of racial discrimination raises the risk of elevated blood pressure, a partial explanation of why blacks suffer more hypertension than whites. The study showed that self-reported racial discrimination is just as harmful as any of the commonly named “lifestyle” culprits: lack of exercise, smoking, a high-fat or high-salt diet.
Traditionally, epidemiology had “adjusted” for race and class to flush out specific biological pathways behind disease. Krieger argued that racism was itself a causal exposure for disease. She went on to develop a scientifically validated research instrument for measuring people’s experiences of racial discrimination—one now used by researchers studying a wide array of health outcomes, from hypertension to tobacco use to depression.
Other HSPH faculty helped write Unequal Treatment, a landmark 2003 report on racial and ethnic disparities in American health care. Among its findings: Even after overcoming barriers to obtaining health care, African Americans and other minority populations were less likely to receive procedures such as coronary bypass operations, kidney dialysis, and kidney transplants.