Abstract
OBJECTIVE: We conducted a meta-analysis and systematic review of published randomized controlled trials (RCTs) to evaluate the impact of financial incentives (FI) on objectively-measured physical activity (PA) and weight loss (WL) in adults with sedentary behavior or chronic health conditions. EVIDENCE REVIEW: We performed a systematic search for RCTs published in English indexed in PubMed, Embase, or Web of Science through July 27, 2017. We limited our search to RCTs that involved an FI intervention with a monetary component, objectively-measured PA or WL outcomes, samples with either sedentary lifestyles or chronic health conditions, and a comparator group that did not receive performance-contingent FI. We calculated the mean difference and standardized mean difference (SMD) for each study and used a random effects model to summarize intervention efficacy. We used the Jadad scoring tool to assess the quality of the identified articles. RESULTS: We abstracted data from 11 RCTs. Two of the 11 included studies focused on PA, totaling 126 intervention and 116 control subjects. Nine RCTs evaluated the effect of FI on WL, totaling 1,799 intervention and 1,483 control subjects. The combined estimate for change in daily steps was 940 (95%CI [306-1,574]) more in PA intervention groups than in control groups and 2.36 (95%CI [1.80-2.93]) more kilograms lost by WL intervention groups compared to control groups. The overall estimated SMD for both outcomes combined was 0.395 (95%CI [0.243-0.546; p<0.001]), favoring FI interventions. CONCLUSION: FI interventions are efficacious in increasing PA and WL in adults with chronic conditions or sedentary adults. Public health programs to increase PA or prevent chronic disease should consider incorporating FI to improve outcomes.