Objective: To evaluate the costs and effects of incremental components of a weight-loss program.
Design: A 3-arm, 12-month randomized controlled clinical trial to evaluate 3 incremental levels of intervention intensity.
Subjects/setting: The study included 588 individuals (BMI > 25 kg/m2) in a freestanding health maintenance organizalion and achieved an 81% completion rate.
Intervention: Using a cognitive behavioral approach for tailoring lifestyle modification goals, the incremental levels of intervention included a) a workbook alone, b) the addition of computerized tailoring using onsite computer kiosks with touch screen monitors, and c) the addition of both computers and staff consultation.
Main outcome measures: Endpoints included weight parameters, lipid profile, plasma glucose, blood pressure, intervention costs, dietary intake, and physical activity.
Statistical analysis performed: Study endpoints were analyzed using analysis of variance for normally distributed variables and analysis of covariance to control for any baseline differences. Regression and correlation analysis assessed the relationship between weight loss and other variables.
Results: For the increasing levels of intervention intensity, the mean 12-month weight losses were 2.2, 4.7, and 7.4 pounds, with the respective cost per participant being $12.33, $41.99, and $133.74. The decreases in mean BMIs for these respective intervelation levels were 0.4, 0.9 and 1.2. All groups reported a decrease in energy and fat intake and an increase in blocks walked (P<.01). Intervention variables that correlated with weight loss included more computer log-ons, achieving computer-selected goals, more self-monitoring, increased walking, and decreased energy and fat intake, as well as higher attendance in staff consultation group sessions for that treatment condition. Weight loss correlated with decreases in fasting glucose and blood pressure.
Applications/conclusions: In a weight-loss program, computers can facilitate selecting behavioral change goals. More frequent usage resulted in greater weight loss. Staff counseling to augment the computer intervention achieved the most weight loss.