The effectiveness of financial incentives on clinical outcomes of cardiovascular disease risk factors: A systematic review and meta-analysis

OBJECTIVES: We sought to examine studies that assessed the effects of financial incentives contingent on clinical improvement on factors associated with cardiovascular disease (CVD) risk. STUDY DESIGN: Systematic review and meta-analysis. METHODS: Databases were searched for randomized controlled trials (RCTs). We included only RCTs with incentives contingent on clinical improvement using consistent parameters. Meta-analyses and subgroup analyses were conducted for outcomes: smoking cessation, glycemic control, blood pressure, and serum cholesterol. Analyses were conducted using Cochrane Review Manager software. Study quality was assessed with RoB 2.0. RESULTS: Data from 43 trials were analyzed: 18 smoking cessation (n = 15,772), 19 wt loss (n = 4416), three glycemic control (n = 418), two hypercholesterolemia trials (n = 543), and one hypertension trial (n = 207). Studies' duration varied from three months to two years. Meta-analyses showed reductions in smoking [risk ratio (RR) 1.56, 95% CI 1.42 to 1.72], change in body weight (kg) [mean difference (MD) -1.2, 95% CI -1.57 to -0.84], and glycated haemoglobin (HbA1c) (%) (MD of -0.43, 95% CI -0.69 to -0.18) by the end of the study period. The analysis of the two studies on low-density lipoprotein cholesterol (LDL-C) (mg/dL) (MD-0.3, 95% CI -4.34 to 3.73) did not reveal a significant effect. CONCLUSIONS: Financial incentives can effectively promote smoking cessation and modest weight loss. Evidence for their effect on glycemic control was promising but limited, while no significant effects were found for LDL-C or blood pressure. Incentives based on clinical outcomes should be assessed for their long-term applicability in managing chronic diseases.