May 10, 2019 – As nurses in the U.S. celebrate National Nurses Week (May 6-12, 2019), Harvard T.H. Chan School of Public Health researchers want them to know that they can contribute valuable information to improve the health of people worldwide—by signing up to be part of the Nurses’ Health Study 3 (NHS3).
Launched in 2010, NHS3 follows on the heels of the iconic Nurses’ Health Study (which began in 1976, with 121,700 participants) and the Nurses’ Health Study II (launched in 1989, with 116,430 participants). All three are prospective cohort studies—studies that examine a group of people over time—that have gathered large amounts of data from nurses through periodic questionnaires and biological samples. The studies have uncovered a wealth of information on diet and lifestyle factors and environmental exposures that influence the risk of chronic diseases in women, generated hundreds of research papers, and uncovered important findings such as the health dangers linked with trans fats and sugar-sweetened beverages.
Dozens of clinicians, epidemiologists, and statisticians from multiple disciplines have been involved in the studies—from Harvard Chan School, from the Channing Division of Network Medicine at Brigham and Women’s Hospital (BWH), from Harvard Medical School, and from other Harvard-affiliated hospitals.
A related study—the Growing Up Today Study (GUTS)—includes nearly 28,000 children of Nurses’ Health Study II participants and looks at the factors that influence weight change and health over the course of a person’s life.
“These studies have made huge contributions to health and medicine and to our understanding of major chronic diseases, including diabetes, breast cancer, heart disease, and more,” said Jorge Chavarro, associate professor of nutrition and epidemiology at Harvard Chan School and principal investigator of NHS3. “They have been enormously influential both in terms of generating science and changing public policies.”
He said there are some key differences between the first two Nurses’ Health Studies and NHS3:
- NHS3 is more racially and ethnically diverse than the first two Nurses’ Health Studies, and it includes male as well as female nurses, to mirror trends in the nursing profession.
- NHS3 is gathering more complete information regarding reproductive health. In the first two studies, such data was usually gathered post-pregnancy; NHS3 is soliciting information, in real time when possible, both during women’s pregnancies and when they are considering getting pregnant.
- NHS3 has a stronger focus on environmental and occupational health.
- While the first two studies used mailed questionnaires, the third is gathering data online, allowing researchers to customize questions to participants’ life events and circumstances.
There’s a new NHS3 website and researchers are stepping up their efforts to recruit additional nurses, with a goal of recruiting at least an additional 55,000 participants in order to reach a target enrollment of 100,000.
Current and upcoming projects
Researchers are working on several new grant-funded projects that make use of data from NHS3 and the other cohorts.
Peter James, former research associate at Harvard Chan School and now an assistant professor at Harvard Medical School, is using NHS3 data to examine links between women’s physical activity, sleep, and obesity using data from GPS-enabled smartphones and wearable activity trackers.
Jaime Hart, assistant professor in the Department of Environmental Health, using GUTS data, is looking at the effect of air pollution and chemical exposures on male fertility, using data from mobile monitoring devices.
Andrea Roberts, research scientist in the Department of Environmental Health, will study genetic and biological data from NHS II and NHS3 participants to learn more about why women who experience abuse as children are more likely than other women to have children with neurodevelopmental problems.
In addition, two federal infrastructure grants will provide management and maintenance support for NHS3 and some of the other cohorts.
One grant, from the National Institute of Environmental Health Sciences, will help co-principal investigators Chavarro and Francine Laden, professor of environmental epidemiology at Harvard Chan, build NHS3 infrastructure to support environmental epidemiology research. A second grant, from the National Heart, Lung and Blood Institute and led by co-principal investigators Chavarro and JoAnn Manson, professor in the Department of Epidemiology and chief of the Division of Preventive Medicine in the Department of Medicine at BWH, will support NHS II, NHS3, and GUTS, with the aim of furthering research on heart and lung diseases. Both infrastructure grants will support activities such as the recruitment of new participants and follow-up with existing ones; the gathering and storing of data and biological and environmental samples; the expanded use of web-based mobile technologies to collect data; and the use of “big data” analytical tools.
Chavarro said that the new infrastructure grants are testament to the School’s extensive experience in developing and managing large cohort studies, as well as the breadth and depth of expertise from across many departments, including Nutrition, Epidemiology, Environmental Health, and Biostatistics, and across partner institutions, primarily the Channing Division of Network Medicine and the Division of Preventive Medicine at Brigham and Women’s Hospital.
He is hopeful that the study team will be able to hit their recruitment goal for NHS3. “Patterns of exposures, behaviors, and risk factors for diseases have changed over time,” Chavarro said. “There are still a lot of things we don’t know, and these cohorts provide the opportunity for us to contribute to public health for many years to come.”