Activity Counseling Trial (ACT)

To develop and evaluate the effectiveness of various intervention approaches, delivered in primary health-care settings, in increasing and maintaining habitual physical activity and cardiorespiratory fitness among sedentary men and women patients. BACKGROUND: A conference on physical activity sponsored by the National Heart, Lung, and Blood Institute (NHLBI) in August 1991 recommended that one priority area for research should be the development and evaluation of interventions for adoption and maintenance of physical activity including interventions that can be incorporated into primary care practice. The 1992 NHLBI Working Group Report on Primary Prevention of Hypertension identified physical inactivity as a risk factor for hypertension. Intervention research applicable to health-care settings is particularly important in light of national recommendations advising health-care professionals to intervene, including Healthy People 2000, the U.S. Preventive Services Task Force reports, and the American Heart Association. DESIGN NARRATIVE: Randomized, multicenter, demonstration and education study. Men and women primary care patients at three sites in Dallas, Palo Alto, and Memphis were randomized to two patient education intervention groups or to a standard care control group of physician advice. Intervention continued for two years for all participants. The primary outcomes were cardiorespiratory fitness and physical activity. Other outcomes were effects on blood pressure, lipoproteins, and weight; the long-term maintenance of these effects; and the cost-effectiveness of various intervention approaches. Recruitment took 15 months and has been completed with the accrual of 874 subjects. The National Institute on Aging participated in the ACT through the addition of a measurement of arterial stiffness involving approximately 700 patients. The NIA tested the hypothesis that increases in physical activity resulting from educational interventions could reduce arterial stiffness.