Addition of Financial Incentives to Mailed Outreach for Promoting Colorectal Cancer Screening: A Systematic Review and Meta-analysis

IMPORTANCE: Although screening decreases incidence of and mortality from colorectal cancer (CRC), screening rates are low. Health-promoting financial incentives may increase uptake of cancer screening. OBJECTIVE: To evaluate the relative and absolute benefit associated with adding financial incentives to the uptake of CRC screening. DATA SOURCES: PubMed, Cochrane Central Register of Controlled Trials, and Web of Science were searched from inception to July 31, 2020. Keywords and Medical Subject Headings terms were used to identify published studies on the topic. The search strategy identified 835 studies. STUDY SELECTION: Randomized clinical trials (RCTs) were selected that involved adults older than 50 years who were eligible for CRC screening, who received either various forms of financial incentives along with mailed outreach or no financial incentives but mailed outreach and reminders alone, and who reported screening completion by using recommended tests at different time points. Observational or nonrandomized studies and a few RCTs were excluded. DATA EXTRACTION AND SYNTHESIS: The review was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). Data were abstracted and risk of bias was assessed by 2 independent reviewers. Random-effects meta-analysis was conducted, heterogeneity was examined through subgroup analysis and metaregression, and quality of evidence was appraised. MAIN OUTCOMES AND MEASURES: The primary outcome was CRC screening completion within 12 months of receiving the intervention. RESULTS: A total of 8 RCTs that were conducted in the United States and reported between January 1, 2014, and December 31, 2020, were included. The trials involved 110 644 participants, of whom 53 444 (48.3%) were randomized to the intervention group (received financial incentives) and 57 200 (51.7%) were randomized to the control group (received no financial incentives). Participants were predominantly male, with 59 113 men (53.4%). Low-quality evidence (rated down for risk of bias and heterogeneity) suggested that adding financial incentives may be associated with a small benefit of increasing CRC screening vs no financial incentives (odds ratio [OR], 1.25; 95% CI, 1.05-1.49). With mailed outreach having a 30% estimated CRC screening completion rate, adding financial incentives may increase the rate to 33.5% (95% CI, 30.8%-36.2%). On metaregression, the magnitude of benefit decreased as the proportion of participants with low income and/or from racial/ethnic minority groups increased. No significant differences were observed by type of behavioral economic intervention (fixed amount: OR, 1.26 [95% CI, 1.05-1.52] vs lottery: OR, 1.06 [95% CI, 0.80-1.40]; P = .32), amount of incentive (≤$5: OR, 1.09 [95% CI, 1.01-1.18] vs >$5: OR, 1.25 [95% CI, 1.02-1.54]; P = .22), or screening modality (stool-based test: OR, 1.14 [95% CI, 0.92-1.41] vs colonoscopy: OR, 1.63 [95% CI, 1.01-2.64]; P = .18). CONCLUSIONS AND RELEVANCE: Adding financial incentives appeared to be associated with a small benefit of increasing CRC screening uptake, with marginal benefits in underserved populations with adverse social determinants of health. Alternative approaches to enhancing CRC screening uptake are warranted.