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Clue Cohort Study- Clue II (CLUE II)

Cohort Collaboration Contact

If interested in collaborating with the cohort on a project, please contact:

Principal Investigators

  • Kala Visvanathan (Johns Hopkins University)
Cohort Website

Clue Cohort Study -CLUE II - Campaign Against Cancer and Heart Disease

CLUE II was similar to CLUE I in many respects. It was conducted from May through October 1989. Mobile trailers were used that operated in all areas of the county and at all times of day except between 1 and 6 a.m. Brief medical histories and blood pressure readings were taken, and 20 ml of blood was drawn into heparinized Vacutainers. Specimens were refrigerated at once, and processed within 24 hours. Plasma, buffy coat, and red blood cells have been preserved at -70°C. A total of 32,894 persons participated, of whom 25,079 gave Washington County, MD addresses. Comparisons with published figures from the 1990 Census indicated that approximately 30 percent of adult residents had participated. As in CLUE I, women and the better educated had higher than average participation rates, as did the age group 45 to 70 years. Data obtained at baseline include age, race, sex, marital status, time since last menstrual period, smoking history, blood pressure, medication use, hormone use, height and weight currently and at age 21. Participants were given a food frequency questionnaire to complete at home and asked to return it (80%) with a toenail clipping for trace metal assays (76%). Cholesterol results were mailed to participants within a few days of blood draw, along with guidelines for physician referral.
Information has been collected from this cohort as far back as 1963 and as recently as 2007 from the following sources: private censuses conducted in 1963 and 1975, questionnaires completed at the times of blood donation, and follow-up information from questionnaires administered in 1996, 1998, 2000, 2003, and 2007.

Cancer has developed in 8100 CLUE II participants, and plasma remains for 98 percent of these cases.

Over a third of the participants in CLUE I also participated in CLUE II (9132) with 8394 forming the Odyssey Cohort. DNA has been extracted for 99% of the Odyssey Cohort.