Landmark Research

Nurses' Health Study

The Nurses' Health Study (NHS) is considered the "grandmother" of women's health studies and represents the single largest cohort study of women, which has resulted in more than 265 published scientific papers. The NHS was established in 1976 to study the relationship between the use of oral contraceptives and cigarette smoking and the risk of major illnesses. For a variety of reasons, including the dedication and commitment of the participants, the scope and range of the study has broadened over time to evaluate the implications of various lifestyle factors such as exercise and diet on women's health.

The study was comprised of data from 127,000 nurses between the ages of 30 and 55. Participants receive detailed questionnaires every 2 years in which they report medical histories, daily diet habits and major life events that have occurred in the past 24 months.

The response rate averages 90 percent, and the data compiled from the study is now equivalent to more than 600,000 typed pages.

Physicians' Health Study

Brigham and Women's Hospital is responsible for two landmark studies in the area of men's health: The Physicians' Health I and the Physicians' Health Study II.

The Physicians' Health Study I, established in 1982 was a randomized clinical trial designed to test two theories:

• that daily low-dose aspirin use reduces the risk of cardiovascular disease
• to evaluate the effectiveness of beta carotene to prevent skin cancer.

The Physicians' Health Study I consisted of 22,071 male physicians between the ages of 40 and 84.

The aspirin component of the study was terminated early when the study results provided statistically extreme evidence that demonstrated 325 mg of aspirin taken every other day dramatically reduced men's risk of a first heart attack.

The beta carotene component of the Physicians' Health Study I concluded in 1995. The study revealed that beta carotene had neither a beneficial nor an adverse effect in preventing skin cancer.

The Physicians' Health Study II, established in 1996, is an on-going clinical trial designed to evaluate the benefits and risks associated with beta-carotene, vitamin E, vitamin C and multivitamin supplements in the primary prevention of cancer, cardiovascular disease, and eye diseases.

The study consists of 15,000 healthy male physicians age 55 and older.

Women's Health Initiative

In 1993, Brigham and Women's Hospital was selected by the National Institutes of Health as one of 16 Vanguard Centers to participate in the largest women's research study undertaken in the United States - The Women's Health Initiative.

The Women's Health Initiative is a national, multi-center, 15-year, $625 million study that will examine the prevention of cardiovascular disease, breast cancer, colon cancer, and osteoporosis through randomized clinical trials involving hormone replacement therapy, low-fat diet, and intake of calcium and vitamin D supplements. The study will also analyze the relationship between the risk of disease and weight, blood pressure, diet, and physical activity.

The study is being conducted among 160,000 women aged 50-79. Approximately 60,000 women are enrolled in the randomized clinical trial component and an additional 100,000 in the observational component.

BWH, the only Massachusetts hospital selected to participate in the Women's Health Initiative, enrolled more than 5,000 women from the Boston area to participate in the study.

BWH's principal investigator of the Women's Health Initiative is JoAnne Manson, MD, Co-Director of Women's Health in the Division of Preventive Medicine in the Department of Medicine at BWH.