Skip left side navigation and go to content
graphic banner of a group of doctors posing in their lab

Practice-Based Opportunity for Promotion of Weight Reduction Trials (POWER Trials)

Project Period: 9/25/2006 - 6/30/2011
Contact: Dr. Barbara Wells

The purpose of this program was to conduct separate, five-year randomized control trials (RCTs) to test the effectiveness of interventions delivered in routine clinical practice on achieving weight loss in obese patients with at least one additional cardiovascular risk factor. Three studies were funded and all shared the same primary outcome measure: change of weight 24 months following randomization (1)

The first RCT targeted 390 obese patients, with two or more metabolic syndrome components, in 6 primary care practices. This three-arm trial compared minimal care, brief lifestyle counseling, and enhanced lifestyle counseling with either meal replacements or weight loss medication. In addition to weight change, this RCT assessed change in metabolic syndrome prevalence, HOMA, C-reactive protein, lipid levels, blood pressure, waist circumference, as well as costs, mood, quality of life, sexual functioning, and other psychological and behavioral variables. Enhanced lifestyle counseling, used with meal replacements or orlistat, produced an average loss of 4.3 kg. One third of these participants lost = 5% of their initial weight. Weight loss was also associated with improvements in CVD risk factors. Brief lifestyle counseling was not superior to usual care (2).

The second RCT targeted 360 obese, low income, predominantly racial/ethnic minority patients, with a diagnosis of hypertension, who were patients in three community health centers. This two-arm trial compared usual care to lifestyle modification with electronic supports, plus interpersonal and socio-environmental support provided by community health workers and community resource linkages. At 24 months, weight change in the intervention group compared to usual care group was -1.03 kg. Mean systolic blood pressure was not significantly lower in the intervention compared to usual care arm (2).

The third funded study targeted 415 obese patients in two primary care practices with hypertension, hypercholesterolemia, and/or diabetes. A multi-channel, behavioral intervention (telephone, Web, and email contacts) without in-person visits; a multi-channel behavioral intervention with in-person (predominantly group sessions) along with telephone, Web and email contacts; and usual medical care with self-directed weight approaches were compared. Blood pressure and hypertension control will be measured, as well as lipid levels, HOMA-IR index, and Framingham Risk Score. At 24 months, the mean change in weight from baseline was -4.6 kg in the group receiving remote support only, and -5.1 kg in the group receiving in-person support. The percentage of participants who lost 5% or more of their initial weight was 38.2% in the group receiving remote support only, and 41.4% in the group receiving in-person support. The change in weight from baseline did not differ significantly between the two intervention groups (3).

Selected References:

Wells, B. (2009). Weight Loss in Obese Adults with Cardiovascular Risk Factors: Three Randomized Control Trials to Assess Interventions in Clinical Practices. Obesity and Weight Management. 5(5): 207-209.

Wadden TA, Volger, S, Sarwer, DB, Vetter, ML, Tsai, AG, Berkowitz, RI, Kumanyika, S, Schmitz, KH, Diewald, LK, Barg, R, Chittams, J, Moore, R (2011). A Two-Year Randomized Trial of Obesity Treatment in Primary Care Practice. New England Journal of Medicine. 365(20). doi: 10.1056/NEJMoa1109220

Bennett, GG, Warner, ET, Glasgow, RE, Askew, S, Goldman, J, Ritzwoller, DP, Emmons, KM, Rosner, BA, Colditz, GA for the Be Fit, Be Well Study Investigators. (2012). Obesity Treatment for Socioeconomically Disadvantaged Patients in Primary Care Practice. Arch Intern Med. doi:10.1001/archinternmed.2012.1

Appel, LJ., Clark, JM., Yeh, HC, Wang, NY, Coughlin, JW, Daumit, G, Miller, ER, Dalcin, A, Jerome, GJ, Geller, S, Noronha, G, Pozefsky, T, Charleston, Reynolds, JB, Durking, N, Rubin, RR, Louise, TA, Brancati, FL (2011). Comparative Effectiveness of Weight-Loss Interventions in Clinical Practice. New England Journal of Medicine. 365(20). doi: 10.1056/NEJMoa1108660

Last Updated January 2013

NIH Resources
Twitter iconTwitterExternal link Disclaimer         Facebook iconFacebookimage of external link icon         YouTube iconYouTubeimage of external link icon         Google+ iconGoogle+image of external link icon