Effectiveness of incentives to improve the reach of health promotion programs- a systematic review and meta-analysis.

The reach (i.e., enrollment, engagement, and retention) of health promotion evidence-based programs (EBPs) at the participant level has been challenging. Incentives based on behavioral economics may be used to improve EBP reach. We aimed to systematically review and synthesize the evidence of the effectiveness of incentives as a dissemination strategy to increase EBP reach. We conducted a literature search in PubMed, SCOPUS, EMBASE, Cochrane Review and Cochrane CENTRAL for articles published between January 2000 and March 2020 to identify incentive strategies used to increase program reach among health promotion EBPs. Inclusion criteria included studies published in English, experimental or quasi-experimental designs, comparison of incentive to non-incentive or control strategies, and reported on reach (n = 35 health promotion studies). Monetary incentives using cash and a fixed schedule of reinforcement were the most used incentive schemes (71%). Incentives alone or combined with other strategies as a multicomponent approach were effective in improving program enrollment, engagement, and retention. Specifically, incentive strategies were associated with higher odds of program enrollment (odds ratio [OR], 2.78; 95% confidence interval [CI], 1.82-4.24; n = 10) and retention (OR, 2.54, 95% CI, 1.34-4.85; n = 9) with considerable heterogeneity (I = 94% and 91%, respectively). Incentives are a promising individual-level dissemination strategy to improve the reach of health promotion EBPs. However, understanding the optimal amount, type, frequency, and target of incentives, and how incentives fit in a multicomponent approach in different contexts requires further research.