International expert on study design to head Stanford Prevention Research Center

- By Susan Ipaktchian

John Ioannidis

The Stanford Prevention Research Center is known for its groundbreaking work in identifying ways that individuals can control and prevent such disorders as heart disease, diabetes, obesity and high blood pressure. And its newest leader wants to expand that expertise by focusing on “population health” — a broad-based approach aimed at devising solutions to help communities and nations stave off the growing epidemic of these chronic illnesses.

John Ioannidis, MD, DSc, will take over as division chief of the SPRC on Sept. 1. He has been serving as professor and chair of hygiene and epidemiology at the University of Ioannina School of Medicine in Greece. The former division chief, Stephen Fortmann, MD, is now a senior investigator at the Kaiser Permanente Center for Health Research in Portland, Ore.

Ioannidis, 45, said the reputation of the Stanford Prevention Research Center is what drew him to the position.

“Some of the most important discoveries in public health were found here, and some of the most important refutations of previous misconceptions were also made here,” Ioannidis said of the Stanford center, which among other things established the link between exercise, nutrition and improved cholesterol levels in preventing heart disease. “There is an opportunity to grow that excellent tradition further.”

He said he wants to capitalize on the center’s research into how individuals can lessen their risks for heart disease and other chronic disorders by expanding its collaborations with geneticists, biostatisticians and epidemiologists to develop both population-based and personalized approaches to health improvement.

“Some of the obstacles in preventive medicine transcend all types of diseases,” Ioannidis said. “If we can collaborate with experts at Stanford and around the world to develop efficient approaches to overcoming these obstacles, then they could be applied to any type of chronic disease.”

Much of Ioannidis own work involves strengthening the way that research is planned, carried out and reported. He outlined some of the problems he observed in a 2005 essay in PLoS-Medicine titled, “Why most published research findings are false.” The essay remains the most-downloaded article in the history of the Public Library of Science, according to the journal’s media relations office.

For instance, Ioannidis noted that until five years ago, many studies that linked a genetic variant to a specific disease were often later proven wrong. In some cases, it was because the number of samples used in a study was too small; in others, the way the data were reported skewed the results.

But the situation has vastly improved in recent years, he said. Sample sizes are larger, and scientific teams from multiple labs are combining their data, which helps remove the reporting biases. “Pretty much everything that is being published in genetics and genomics can now be replicated with strong credibility,” he said.

“Dr. Ioannidis is the leading clinical research methodologist of his generation,” said Ralph Horwitz, MD, chair of Stanford’s Department of Medicine, which includes the SPRC. “His work on the ‘study of studies’ has reshaped our approach to clinical investigation and created new paradigms in genomic medicine, medical statistics, clinical epidemiology and evidence-based medicine.”

Ioannidis was born in New York City and grew up in Athens. He attended Athens College, and then went on to earn a medical degree and a doctorate in biopathology from the University of Athens School of Medicine. He served a residency in internal medicine at the New England Deaconess Hospital in Boston, and an infectious disease fellowship with the Tufts University School of Medicine.

After serving in various positions with Tufts, Harvard Medical School and the National Institute of Allergy and Infectious Diseases, Ioannidis returned to Greece in 1998 as a faculty member at the University of Ioannina. He is also an adjunct professor of medicine at Tufts and an adjunct professor of epidemiology at Harvard’s School of Public Health.

He is a member of the executive board of the Human Genome Epidemiology Network, president of the Society for Research Synthesis Methodology, a member of the editorial board of 26 leading international journals and editor-in-chief of the European Journal of Clinical Investigation.

Ioannidis has published more than 400 peer-reviewed papers, and more than 40 books and book chapters. He has also received several awards, including the 2007 European Award for Excellence in Clinical Science, and is an elected member of the Association of American Physicians.

He and his wife, Despina Contopoulos-Ioannidis, MD, have one daughter, Angelica.

“We’ve never lived in California, and we’re thrilled about living here,” he said.

About Stanford Medicine

Stanford Medicine is an integrated academic health system comprising the Stanford School of Medicine and adult and pediatric health care delivery systems. Together, they harness the full potential of biomedicine through collaborative research, education and clinical care for patients. For more information, please visit

2023 ISSUE 3

Exploring ways AI is applied to health care