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Activity Counseling Trial (ACT): rationale, design, and methods


Medicine & Science in Sports & Exercise: July 1998 - Volume 30 - Issue 7 - p 1097-1106

Activity Counseling Trial: rationale, design, and methods. Med. Sci. Sports Exerc., Vol. 30, No. 7, pp. 1097-1106, 1998. The Activity Counseling Trial (ACT) is a multicenter, randomized controlled trial to evaluate the effectiveness of interventions to promote physical activity in the primary health care setting. ACT has recruited, evaluated, and randomized 874 men and women 35-75 yr of age who are patients of primary care physicians. Participants were assigned to one of three educational interventions that differ in amount of interpersonal contact and resources required: standard care control, staff-assisted intervention, or staff-counseling intervention. The study is designed to provide 90% power in both men and women to detect a 1.1 kcal·kg−1·day−1 difference in total daily energy expenditure between any two treatment groups, and over 90% power to detect a 7% increase in maximal oxygen uptake, the two primary outcomes. Primary analyses will compare study groups on mean outcome measures at 24 months post-randomization, be adjusted for the baseline value of the outcome measure and for multiple comparisons, and be conducted separately for men and women. Secondary outcomes include comparisons between interventions at 24 months of 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, and at 6 months for primary outcome measures. ACT is the first large-scale behavioral intervention study of physical activity counseling in a clinical setting, includes a generalizable sample of adult men and women and of clinical settings, and examines long-term (24 months) effects. ACT has the potential to make substantial contributions to the understanding of how to promote physical activity in the primary health care setting.

Cooper Institute for Aerobics Research, University of Tennessee, Memphis, Bowman Gray School of Medicine, Stanford University School of Medicine, National Heart, Lung, and Blood Institute

ACT is supported by the National Heart, Lung, and Blood Institute through the following contracts: N01-HC-45135 (S. N. Blair, PI), N01-HC-45136 (A. C. King, PI), N01-HC-45137 (W. B. Applegate, PI), and N01-HC-45138 (T. M. Morgan, PI).

We thank all co-investigators, medical directors, participating physicians, nurses and clinic staff, project coordinators, health educators, laboratory technicians, data coordinators, and secretaries who are contributing to ACT for their hard work and professionalism. We thank Melba Morrow for editorial assistance. We are grateful for the dedicated ACT participants who give of their time and effort to help make the study a success.

Authors two through nine are listed in alphabetical order, and all made equal contribution to the preparation of this report.

Clinical Centers-Cooper Institute for Aerobics Research: Steven N. Blair (Principal Investigator), Andrea Dunn, Larry Gibbons, Benjamin Levine (University of Texas Southwestern Medical Center [UTSWMC]), Peter Snell (UTSWMC), James Sallis (San Diego State University), Bess Marcus (Brown University), Melissa Garcia, Amy Strasner (UTSWMC), Sheila Darroch, Michelle Edwards, Nancy Pierce, Ruth Carpenter, Laura Becker, Christopher Colflesh (UTSWMC), Jerome Differding, James Kampert, Alan Levitt, Stephanie Parker, Janet Chandler, Kia Vaandrager, Harold W. Kohl III, William J. Wilkinson. Stanford University School of Medicine: Abby King (Principal Investigator), William Haskell, Cheryl Albright, Leslie Pruitt, Lisa Palmer, Wayne Phillips, Ami Laws, Marcia Stefanick, Irene Etter, Kelley Callahan, Marina Nicolae, Alisa Kamigaki, Steven Park, Julie Peltz, Lynne Alexander, Jennifer Almand. University of Tennessee, Memphis: William B. Applegate (Principal Investigator), Robert C. Klesges (University of Memphis), Mary O'Toole, Stephen T. Miller, Karen C. Johnson, Joyce Banton, Mace Coday, Jay Lee Taylor, Beate Griffin, Judith Soberman, Jan Elam, Veronica Horton, Jerold Loftin.

Project Office (National Heart, Lung, and Blood Institute)-Denise Simons-Morton (Project Officer), P. Scott Allender, Jeffrey Cutler, Eva Obarzanek, Joanna Shih, John Taylor, Carolyn Voorhees, Colleen Brown, Nicole Lewis.

Clinical Coordinating Center-Bowman Gray School of Medicine: Timothy Morgan (Principal Investigator), Roger Anderson, Stuart Cohen, Mark Espeland, Walter Ettinger, Elizabeth Mayer-Davis, Michael Miller, Jack Rejeski (Wake Forest University), Paul Ribisl (Wake Forest University), Mary Ann Sevick, Mara Vitolins, Robert Amoroso, Susan Anthony, Timothy Craven, Kathy Dotson, Rebecca Fussell, Darrin Harris, Patricia Hogan, Susan Margitic, Stephanie Reece, Carol Wasilauskas.

Data and Safety Monitoring Board-Albert Oberman (Chair), Rod Dishman, Patricia Dubbert, Elisha Lee, I-Min Lee, Russell Pate.

Central Laboratory-Penn Medical Laboratories: David Robbins, Marilyn Cadorette.

© Williams & Wilkins 1998. All Rights Reserved.