A stepped-care intervention for weight loss was nearly as effective as a standard behavioral diet-and-exercise approach but only cost about half as much, in a study of 363 overweight adults reported in the June 27 JAMA.
The overall weight loss during the 18-month intervention was greater with the standard approach. But, at the conclusion of the study, when both groups of subjects had regained some of their lost weight, the 1.3-kg difference between the two was not significant.
Moreover, the cost of the stepped-care program was estimated to be $785/person, compared with a $1,357/person price tag for the standard approach, according to John M. Jakicic, Ph.D., of the University of Pittsburgh, and his associates.
The stepped-care approach involves low-intensity intervention at first, which is escalated only if subjects fail to achieve their weight-loss milestones according to a fixed schedule. Stepped care has proved effective in the treatment of other conditions such as eating disorders, substance abuse, and anxiety disorders, the investigators noted.
In this study, performed at two clinical sites, adults aged 18-55 years with a body mass index between 25 kg/m2 and 40 kg/m2 were randomly assigned to a traditional diet-and-exercise program (165 subjects) or to the stepped-care program (198 subjects). All participants were free of cardiovascular disease as well as metabolic or medical conditions that might affect weight or physical activity.
The two groups received identical recommendations for diet and physical activity, aimed at reducing energy intake as well as fat consumption. They were offered sample meal plans and prescribed exercise that increased to 300 minutes/wk of moderate to vigorous activity by week 24.
For the standard intervention, subjects attended group sessions throughout the 18-month intervention, starting with weekly sessions for 6 weeks, decreasing to bimonthly sessions through 12 months, and further decreasing to monthly sessions for the final 6 months. These sessions focused on adopting and maintaining healthy eating and exercise behaviors, as well as learning strategies to facilitate long-term behavioral change.
For the stepped-care intervention, the content was the same but the "contact frequency, contact type, and other weight-loss strategies were modified, depending on the achievement of specific weight goals at 3-month intervals." In step 1, the subjects were offered one monthly group session and three mailings. If they failed to reach a weight-loss goal, step 2 added a 10-minute phone contact each month. If that also failed, step 3 added a second 10-minute phone call per month.
Step 4 added one individual, in-person session per month. Step 5 added replacement shakes and bars to take the place of one meal and one snack per day. Step 6 replaced one of the telephone contacts with a second individual, in-person session per month.
A total of 260 participants (72%) completed the 18-month intervention.
The pattern of weight loss was different between the two groups. Subjects in the standard-care group lost more weight overall and lost weight more quickly than did those in the stepped-care group.
With the standard intervention, subjects averaged a loss of 9.6 kg at 6 months, compared with a 7.6-kg loss in the stepped-care group. The percentage loss of weight from baseline to 6 months was 10.4% with the standard approach, compared with 8.2% with the stepped-care approach.
At 18 months, weight loss averaged 7.6 kg with the standard intervention and 6.2 kg with stepped care, a nonsignificant difference. The percentage loss of weight from baseline to 18 months was 8.1% and 6.9%, respectively. "The effect size for the difference in absolute weight at 18 months between the groups was 6.3%, and the effect size for the weight loss at 18 months between the groups was 18%," the investigators said.
Viewed another way, similar numbers of subjects in the two groups achieved weight losses of 5% or more, 7% or more, and 10% or more, so the stepped-care approach "may be a viable alternative to traditional [care]," the researchers concluded (JAMA 2012;307:2617-26).
Subjects’ resting heart rate, systolic blood pressure, and diastolic blood pressure decreased significantly in both groups, and there was no significant difference between the two groups. Similarly, subjects’ fitness level, defined as the time to achieve 85% of age-predicted maximal heart rate, improved to the same degree in both groups.
The cost of the standard approach was significantly higher mainly because of the reduced reliance on in-person meetings with stepped care. The incremental cost-effectiveness ratio for stepped care was $127/kg of weight lost, compared with $409/kg for standard care.
"Comparisons with the literature suggest these results are likely to compare favorably with other pharmacologic and behavioral weight loss interventions," Dr. Jakicic and his associates said.