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Definition of Nurses Health Study

Nurses Health Study definition - medical term

The Nurses' Health Study (NHS) was established in 1976 by Dr. Frank Speizer at the Channing Laboratory (Harvard Medical School). Funding was from the National Institutes of Health (NIH). The primary motivation was to investigate the potential long term consequences of the use of oral contraceptives. Registered nurses were selected to be followed prospectively. It was anticipated that, because of their nursing education, they would be able to respond with a high degree of accuracy to brief, technically-worded questionnaires and would be motivated to participate in a long term study. Married registered nurses who were aged 30 to 55 in 1976, who lived in the 11 most populous states and whose nursing boards agreed to supply the study with their members' names and addresses were enrolled in the cohort if they responded to the baseline questionnaire. The original states were California, Connecticut, Florida, Maryland, Massachusetts, Michigan, New Jersey, New York, Ohio, Pennsylvania and Texas. Approximately 122,000 nurses out of the 170,000 mailed responded. Every two years cohort members receive a follow-up questionnaire with questions about diseases and health-related topics including smoking, hormone use and menopausal status.

Because it was recognized that diet and nutrition would play important roles in the development chronic diseases, in 1980, the first food frequency questionnaire was collected. Subsequent diet questionnaires were collected in 1984, 1986 and every four years since. At the request of some of the nurses and with the addition of investigators to the research team interested in quality of life issues, questions related to quality-of-life were added in 1992 and repeated every four years.

Because certain aspects of diet cannot be measured by questionnaire, particularly minerals that become incorporated in food from the soil in which is it grown, the nurses submitted 68,000 sets of toenail samples between the 1982 and 1984 questionnaires. Similarly, to identify potential biomarkers, such as hormone levels and genetic markers, 33,000 blood samples were collected in 1989. These samples are stored and used in case/control analyses. A second blood collection from those who previously gave a sample was conducted in 2000/2001.

As of this writing, response rates to questionnaires are at 90% for each two-year cycle. The Nurses' Health Study II was started, also at the Channing, in 1989. (Based on information kindly provided by the Channing Laboratory.)

The Physicians' Health Study is a comparable large long-term study of men's health issues. See: Physicians Health Study.