Patient Preferences for Lifestyle Management in a Multi-site Randomized Lifestyle Trial for Remission of the Metabolic Syndrome.

Background: Randomized behavioral clinical trials are the gold standard for evaluating efficacy of a behavioral treatment. However, because participants are generally unblinded to treatment, preference for a specific treatment option can lead to biased results and/or reduced treatment efficacy. The purpose was to describe the relative frequency and correlates of existence of a preference and patient preference for either an in-person group-based or a remote self-directed, lifestyle treatment prior to randomization to one of these treatments.

Methods: The Enhanced Lifestyles for Metabolic Syndrome (ELM) trial is a multi-site behavioral clinical trial that compares efficacy of a group-based vs. a self-directed approach to lifestyle change on 2-year remission of the metabolic syndrome. Prior to randomization, participants were asked whether they had a preference for a particular treatment and, if so, which approach they preferred. Baseline data were used for a series of logistic regression models to determine behavioral correlates of treatment preference, independent of socioeconomic factors.

Results: Of the 331 participants, 131 (39.6%) had no preference for either treatment. Among the 200 with a preference, 56 (28.0%) preferred the self-directed program. Strength of a pre-existing habit of eating vegetables on most days was an independent correlate of no preference (adjusted OR, 1.27; 95% CI, 1.01-1.61; p = 0.03) and preference for a self-directed program (adjusted OR, 1.55; 95% CI, 1.09-2.22; p = 0.01).

Conclusion: A pre-existing habit of eating vegetables was associated with no preference and preference for a less intensive lifestyle treatment. Post-treatment follow-up of the trial results will determine if concordance between preference and treatment assignment influences outcomes.