A two-year randomized trial of obesity treatment in primary care practice

Abstract

Background: Calls for primary care providers (PCPs) to offer obese patients behavioral weight-loss counseling have not been accompanied by adequate guidance on how such care could be delivered. This randomized trial compared weight loss during a 2-year period in response to three lifestyle interventions, all delivered by PCPs in collaboration with auxiliary health professionals (lifestyle coaches) in their practices.

Methods: We randomly assigned 390 obese adults in six primary care practices to one of three types of intervention: usual care, consisting of quarterly PCP visits that included education about weight management; brief lifestyle counseling, consisting of quarterly PCP visits combined with brief monthly sessions with lifestyle coaches who instructed participants about behavioral weight control; or enhanced brief lifestyle counseling, which provided the same care as described for the previous intervention but included meal replacements or weight-loss medication (orlistat or sibutramine), chosen by the participants in consultation with the PCPs, to potentially increase weight loss.

Results: Of the 390 participants, 86% completed the 2-year trial, at which time, the mean (±SE) weight loss with usual care, brief lifestyle counseling, and enhanced brief lifestyle counseling was 1.7±0.7, 2.9±0.7, and 4.6±0.7 kg, respectively. Initial weight decreased at least 5% in 21.5%, 26.0%, and 34.9% of the participants in the three groups, respectively. Enhanced lifestyle counseling was superior to usual care on both these measures of success (P=0.003 and P=0.02, respectively), with no other significant differences among the groups. The benefits of enhanced lifestyle counseling remained even after participants given sibutramine were excluded from the analyses. There were no significant differences between the intervention groups in the occurrence of serious adverse events.

Conclusions: Enhanced weight-loss counseling helps about one third of obese patients achieve long-term, clinically meaningful weight loss. (Funded by the National Heart, Lung, and Blood Institute; POWER-UP ClinicalTrials.gov number, NCT00826774.).

Figure 1. Screening, Randomization, and Assessments of Study Participants

Of the 129 participants randomly assigned to enhanced brief lifestyle counseling, 67, 38, and 24 initially chose to use meal replacements, sibutramine, and orlistat, respectively. BMI denotes body-mass index (the weight in kilograms divided by the square of the height in meters).

Figure 2. Estimated Percent Reduction in Baseline Weight over a 24-Month Period in the Intention-to-Treat Population

Figure 3. Categorical Weight Loss at 12 and 24 Months

Panel A shows the percentage of participants in each group in the intention-to-treat population who were at or below their baseline weight at months 12 and 24. (Participants for whom data on weight were missing were assumed to have a weight above the baseline weight.) Panel B shows the percentage of participants who lost 5% or more of their baseline weight, and Panel C shows the percentage of participants who lost 10% or more of their baseline weight. (The percentage of participants who lost 5% or more of their baseline weight includes the percentage who lost 10% or more.)