Brief reportEfficacy of a Weight-Loss Website Based on Positive Deviance: A Randomized Trial
Introduction
The obesity epidemic has widespread adverse health and economic effects.1 Internet-based weight-loss programs could help address the obesity epidemic, as they can be widely disseminated with low costs. Existing Internet-based weight-loss programs have largely promoted weight-loss strategies designed by health professionals, including goal-setting and feedback, and features to promote social interaction.2, 3, 4, 5, 6 These programs have had modest short-term effects, suggesting that exploring alternative approaches may be beneficial.
The present study evaluated the efficacy of using a positive deviance framework to guide the design of an Internet-based weight-loss intervention.7 The central premise of positive deviance is that solutions to population-based problems often exist within a population, and that population members' solutions can be generalized to improve other members' performance.8 Positive deviance uses qualitative research to identify the behaviors of individuals who have obtained rare success (typically top 10% of the population) at achieving specific outcomes. These behaviors are then disseminated through community engagement and behavior modification strategies. Positive deviance has been used in diverse health-related interventions, but has not previously been used in weight-loss interventions.9, 10, 11, 12, 13, 14
The present Internet-based intervention evaluated the efficacy of promoting weight-loss behaviors that were generated from a prior qualitative study of individuals who maintained long-term weight loss of at least 30 lbs (positive deviants).7 It was hypothesized that an Internet-based intervention that disseminated weight-loss behaviors of these positive deviants could promote weight loss among overweight and obese adults.
Section snippets
Design
The study was conducted at a single institution (Penn State Hershey Medical Center) in 2009–2010 with 100 participants randomized to the 12-week AchieveTogether intervention or wait-list control condition with in-person assessments at baseline and post-program (12 weeks). This sample size enabled 90% power to detect a 2.0-kg difference between conditions in the primary outcome of weight loss,3, 6 assuming 20% attrition. Randomization took place at the baseline visit using concealed envelopes.
Participants
Baseline characteristics of participants are shown in Table 1; no significant group differences were observed. At post-program, treatment completers (n=88) were older than those lost to follow-up (n=12; mean age = 50.3 vs 43.4 years, p<0.05); no other differences were noted.
Weight Change and Health Outcomes
Table 2 shows weight-loss and health outcomes among study completers. There was a 2.0-kg difference in weight change between groups (p<0.01). The difference in weight change between groups remained significant with
Discussion
The present study evaluated the efficacy of a website based on positive deviance for disseminating weight-control behaviors used by individuals successful with weight loss.7 In contrast to the expert-driven approach that has guided the design of many other weight-loss websites,3, 6 the AchieveTogether website design was driven by successful solutions that individuals have used to manage their weight.
The use of aggregate qualitative data on weight-loss behaviors from those who successfully lost
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