Epidemiology

View Principal Investigators in Epidemiology

When it comes to understanding the health of populations, the Intramural Research Program (IRP) is ideally structured for the long-term research that supports the field of epidemiology. Studying health patterns and outcomes in large numbers of individuals over long periods of time is no easy task, and our scientists have a number of tools available to them that specifically enable this type of research: stable funding, multi-disciplinary scientific teams, and the world's largest hospital entirely devoted to clinical research — the NIH Clinical Center.

Epidemiology research involves not just epidemiologists, but also geneticists, biologists, sociologists, statisticians, psychologists, bioinformaticians, data scientists, and mathematicians, and of course the study participants. There are several general categories of epidemiological studies:

  • Prospective cohort studies, also known as longitudinal studies, investigate the long-term health outcomes of a group of healthy people.
  • Case-control studies compare individuals with a known health condition to those without it to understand why some individuals become ill and others do not.
  • Cross-sectional studies compare groups at a single point in time.
  • Family studies examine how disease develops in families with inherited predisposition syndromes.

IRP scientists are currently engaged in a wide range of epidemiological studies, including:

  • The Baltimore Longitudinal Study of Aging (BLSA): initiated in 1958 and conducted by the National Institute on Aging (NIA), the BLSA is America's longest-running scientific study of human aging.
  • The Sister Study: this study has enrolled more than 50,000 women with a sister who had breast cancer from across the US and Puerto Rico. Because of their shared environment, genes, and experiences, studying sisters provides a greater chance of identifying risk factors that may help us find ways to prevent breast cancer. The study is run by the National Institute of Environmental Health Sciences (NIEHS).
  • The Agricultural Health Study (AHS): this study explores a wide range of health outcomes among licensed pesticide applicators, as well as their spouses and children, to explore the health effects of exposure to pesticides and other agricultural hazards. The study is a collaboration between the National Cancer Institute (NCI), NIEHS, and the U.S. Environmental Protection Agency (EPA).
  • Connect for Cancer Prevention Cohort Study: this prospective cohort study of U.S. adults, led by the NCI, is designed to investigate the causes of cancer and its outcomes, which may inform new approaches to prevention and early detection.
  • Scientific Evaluation of One or Two Doses of the Bivalent or Nonavalent Prophylactic HPV Vaccines — The ESCUDDO Study: this randomized clinical trial, conducted by the NCI, compares the effectiveness of one-dose and two-dose vaccination against the Human Papilloma Virus (HPV) among 20,000 girls 12 to 16 years old residing in Costa Rica. It also tracks HPV infection among unvaccinated women ages 17 to 20.
  • The Fetal Growth Studies — Singletons and Dichorionic Twins: this study, led by the Eunice Kennedy Shriver National Institute Child Health and Human Development (NICHD), was designed to establish a standard for normal fetal growth and size for gestational age in the U.S. In addition, it aims to describe fetal growth trajectories of twins compared with the standard developed for single births to determine the standard's applicability for monitoring the growth of twins.
  • Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS): this study, conducted by the National Institute on Aging (NIA), is a prospective cohort study of African American and White adults ages 30-64 living in Baltimore City. HANDLS aims to disentangle the relationships among race, socioeconomic status, and health outcomes as they relate to aging.

To learn more about those studies, visit each IRP program's website:

IRP programs provide excellent opportunities for career training and development — from postbaccalaureate to postdoctoral fellowships. Learn more about these opportunities via the NIH Office of Intramural Training and Education.

To find out more about IRP scientists who carry out epidemiological studies, visit any of NIH's Scientific Interest Groups focused on Epidemiology.