The challenge of sustainability: Long-term results from the Fifty-Fifty peer group-based intervention in cardiovascular risk factors.

Background: The Fifty-Fifty trial demonstrated that a peer-group-based intervention was able to improve healthy behaviors in individuals with cardiovascular (CV) risk factors immediately post-intervention.

Objectives: To determine the long-term sustainability of a one-year peer-group-based intervention focused on CV health and behavior.

Methods: A total of 543 adults aged 25 to 50 years with at least 1 CV risk factor were screened and recruited, received initial training through workshops, and were then randomized 1:1 to a peer-group-based intervention group (IG) or a self-management control group (CG) for 12 months. At a median of 52 months from baseline, 321 participants were re-assessed (~60% retention). The primary outcome was the mean change in a composite health score related to blood pressure, exercise, weight, alimentation, and tobacco use (Fuster-BEWAT score [FBS], range 0-15). Intervention effects were assessed using linear-mixed effects models.

Results: The mean age of retained participants was 48.0 years (SD: 5.4), and 73% were female. Consistent with previous results, the change of overall FBS was significantly greater in the IG than in the CG at 12-month follow-up (between-group difference, 0.60 points; 95% CI, 0.08-1.12; P = .025). Assessment of long-term sustainability (52-month follow-up) showed that there were no between-group differences in the mean overall FBS (IG mean score, 8.52; 95% CI, 7.97-9.07 vs CG mean score, 8.51; 95% CI, 7.93-9.10; P = .972) or in the change of overall FBS from screening (IG mean change, 0.64; 95% CI, 0.00-1.28; CG mean change, 0.46; 95% CI, -0.20-1.12; P = .497).

Conclusions: A one-year peer-group-based intervention showed favorable results at immediate post-intervention but did not demonstrate significant differences between the IG and CG at 52 months. Combination of an initial training period (workshops) with the maintenance of peer-support groups or other re-intervention strategies may be required to achieve sustained effects on healthy behaviors.

Trial Registration: ClinicalTrials.gov identifier NCT02367963. Registered (https://clinicaltrials.gov/show/NCT02367963).