DESIGN AND METHODS OF A MULTICENTER TRIAL OF PHYSICAL ACTIVITY COUNSELING IN PRIMARY CARE 1346

Abstract

Few studies have examined long-term effects on physical activity and fitness of counseling in the primary care clinical setting. The Activity Counseling Trial is an NHLBI-sponsored multi-center randomized clinical trial to evaluate the efficacy of primary care physical activity behavioral interventions. About 810 sedentary generally healthy 35-75 year-old patients of primary care physicians are enrolled and randomly assigned to three groups. The control group receives physician advice; the two interventions groups receive one of two behavioral intervention programs that differ in resources required. Participants receive two years of intervention and follow-up. Primary outcome measures are: (1) kilocalories expended in physical activity(kcal·kg-1·day-1) measured by 7-day physical activity recall and (2) maximal oxygen uptake (VO2max)(L·min-1) measured by maximal treadmill test using a standardized protocol. Primary analyses will compare study groups on mean outcome measures at 2 years post-randomization, be adjusted for baseline value of outcome measure and multiple comparisons, and be conducted for men and women separately. Secondary outcomes include comparisons at six months of the primary outcome measures, factors related to cardiovascular disease (blood lipids/lipoproteins, blood pressure, body composition, plasma insulin, fibrinogen, dietary intake, smoking, heart rate variability), psychosocial effects, and cost-effectiveness. Identifying effective strategies for physical activity counseling in primary care should help increase physical activity nationwide.