Effectiveness of Incentives for Improving Diabetes-Related Health Indicators in Chronic Disease Lifestyle Modification Programs: a Systematic Review and Meta-Analysis

INTRODUCTION: We examined the effectiveness of providing incentives to participants in lifestyle modification programs to improve diabetes-related health indicators: body weight, body mass index (BMI), blood pressure, cholesterol, and hemoglobin A(1C) (HbA(1C)). We also examined the potential effect of 4 different incentive domains (ie, type, monetary value, attainment certainty, and schedule) on those indicators. METHODS: We searched Medline, Embase, PsycINFO, and Cochrane Library to identify relevant studies published from January 2008 through August 2021. We used a random-effects model to pool study results and examine between-study heterogeneity by using the I (2) statistic and the Cochran Q test. We also conducted moderator analyses by using a mixed-effects model to examine differences between subgroups of incentive domains (eg, incentive type [cash vs other types]). RESULTS: Our search yielded 10,965 articles, of which 19 randomized controlled trials met our selection criteria. The random-effects model revealed that, relative to the control group, the incentive group had significant reductions in weight (−1.85kg; 95% CI, −2.40 to −1.29; P < .001), BMI (−0.47kg/m(2); 95% CI, −0.71 to −0.22; P < .001), and both systolic blood pressure (−2.59 mm HG; 95% CI, −4.98 to −0.20; P = .03) and diastolic blood pressure (−2.62 mm Hg; 95% CI, −4.61 to −0.64; P = .01). A reduction in cholesterol level was noted but was not significant (−2.81 mg/dL; 95% CI, −8.89 to −3.28; P = .37). One study found a significant reduction in hemoglobin A(1c) (−0.17%; 95% CI, −0.30% to −0.05%; P < .05). The moderator analyses showed that the incentive effect did not vary significantly between the subgroups of the incentive domains, except on weight loss for the attainment certainty domain, suggesting that a variety of incentive subgroups could be equally useful. CONCLUSION: Providing incentives in lifestyle modification programs is a promising strategy to decrease weight, BMI, and blood pressure.