BOX 3.2 Frequently Referenced Prospective Cohort Studies
American Cancer Society’s Cancer Prevention Studies
Cancer Prevention Study I (CPS I)
A prospective study of approximately one million men and women. Enrollment started in 1959 and follow-up ran through 1972, with mortality being the primary outcome measure (ACS, 2001). Enrollment was household-based, and all members of a household age 30 or older were included in the study if at least one household member was age 45 or older. Upon entering the study, participants completed questionnaires assessing lifestyle factors (e.g., occupation, diet, and tobacco use), reproductive factors (in women), personal and family history of cancer, as well as anthropometric and demographic information. After this, questionnaires were sent to participants at regular intervals to update tobacco use and assess vital status.
Cancer Prevention Study II (CPS II)
A prospective study of approximately 1.2 million men and women (ACS, 2001). Started in 1982 and still ongoing, the primary aim of CPS II is to assess the effect that lifestyle and environmental factors have on cancer development. As with CPS I, enrollment in CPS II was household-based and included all household members age 30 or older if at least one member was age 45 or older. A range of lifestyle and other factors were assessed by questionnaire at study enrollment. The study’s main outcome measure is mortality, which is assessed biennially through links with the National Death Index.
Health Professionals Follow-Up Study
A prospective study of approximately 52,000 male health professionals—including dentists, optometrists, osteopaths, podiatrists, pharmacists, and veterinarians (Harvard School of Public Health, 2001). Started in 1986 in men ages 40–75, it is still ongoing. The primary aim of the Health Professionals Follow-Up Study is to assess the effect of lifestyle on the risk of chronic disease, particularly cancer and cardiovascular disease. Data are gathered largely through biennial questionnaires that ask participants detailed questions about their disease status as well as about their lifestyle and personal characteristics.
Male British Doctors Study
A prospective mortality study of 34,000 male British doctors, which started in 1951 and is still ongoing (Doll et al., 1994). The study’s initial aim was to build a body of evidence linking tobacco use to chronic disease. While the questionnaire at enrollment focused largely on tobacco use, subsequent follow-up questionnaires added questions related to alcohol use, aspirin use, disease status, and certain personal characteristics.
Nurses’ Health Study
A prospective study of approximately 120,000 female registered nurses, which is primarily designed to assess the effect of lifestyle on the risk of chronic disease, particularly cancer and cardiovascular disease (Colditz, 1995). Started in 1976 in women ages 30–55, the Nurses’ Health Study is still ongoing. Data are gathered primarily through biennial questionnaires that ask participants detailed questions about their disease status as well as their lifestyle and personal characteristics. To provide a more accurate accounting of the intake of certain minerals, participants provided toenail samples in 1982. In 1989, participants provided blood samples to allow the study of potential disease biomarkers.