Pinpointing associations between risk factors and particular health effects is tricky, says Karin Michels, associate professor of epidemiology at Harvard School of Public Health and associate professor of obstetrics, gynecology, and reproductive health at Harvard Medical School. That’s because there are typically many factors—eating or exercise habits or alcohol consumption, for instance—that can all be affecting health at the same time. So researchers examining the effects of one factor have to statistically rule out other so-called “confounding factors.”
Michels outlines this central public health research challenge in an excerpt in the September 2011 issue of Harvard Magazine. The excerpt was adapted from an essay titled “Medical Detectives” in the forthcoming book, The Harvard Sampler: Liberal Education for the Twenty-First Century, a collection of faculty-written essays about topics at the forefront of academia in the twenty-first century.