Effect of a Stepped-Care Intervention Approach on Weight Loss in Adults: A Randomized Clinical Trial
Does a stepped-care weight loss intervention result in greater weight loss compared to standard behavioral weight loss interventions?
This was a randomized clinical trial of overweight and obese adults, defined as having a body mass index (BMI) between 25 and 40 kg/m2. Subjects were between the ages of 18 and 55 years and enrolled at two university sites affiliated with academic medical centers in the United States as part of the Step-Up Study between May 2008 and February 2010. All participants were placed on a low-calorie diet and prescribed increases in physical activity. All were provided group counseling sessions ranging from weekly to monthly over an 18-month period. The stepped-care intervention group was assigned a fixed program. Counseling frequency, type, and weight loss strategies could be modified every 3 months for the stepped-care group in response to observed weight loss. The primary outcome of interest was mean weight change over 18 months. Secondary outcomes included resting heart rate and blood pressure, waist circumference, body composition, fitness, physical activity, dietary intake, and program cost.
A total of 363 participants were randomized (33% white, 83% female), of which 260 (71.6%) provided information on mean weight change over the 18-month period. The 18-month intervention resulted in mean weight change from 93.1 kg to 85.6 kg in the standard-care group and from 92.7 kg to 86.4 kg in the stepped-care group. The percentage change in weight from baseline to 18 months was −8.1% (95% confidence interval [CI], −9.4% to −6.9%) in the standard-care group (p < 0.001) compared with −6.9% (95% CI, −8.0% to −5.8%) in the stepped-care group (p < 0.001). The between-group difference in 18-month weight loss was not statistically different (−1.3 kg [95% CI, −2.8 to 0.2 kg]; p = 0.09) between the two groups; however, there was a significant group x time interaction effect (p = 0.03). The cost per participant was $1,357 (95% CI, $1,272-$1,442) for the standard group versus $785 (95% CI, $739-$830) for the stepped-care group (p < 0.001). Both groups had significant and comparable improvements in resting heart rate, blood pressure level, and fitness.
The investigators concluded that among overweight and obese adults, a standard-care intervention resulted in greater weight loss compared to a stepped-care intervention; however, stepped-care also resulted in significant weight loss at a lower cost.
Given the numbers of Americans who are overweight or obese, the cost of weight programs is a significant concern. Both programs used in this trial achieved significant weight loss; however, both programs had a high percentage of subjects drop for the study. Improving our understanding of long-term, effective interventions that are not cost-prohibitive is warranted.
Keywords: Waist Circumference, Caloric Restriction, Body Mass Index, Overweight, Weight Loss, Counseling, Blood Pressure, Diet, United States
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