International guidelines promote screening by faecal tests in asymptomatic individuals at average risk of colorectal cancer (CRC), but uptake does not reach recommended levels in most countries. The aim of this study was to synthetize evidence on (a) interventions aiming to increase uptake of faecal tests for CRC screening, in asymptomatic individuals at average risk of CRC, (b) interventions that targeted general practitioner (GP) involvement and (c) interventions that targeted nonresponders or disadvantaged groups. A systematic review of randomized-controlled trials, searching PubMed, Embase and the Cochrane Library database, based on the Cochrane's Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2015 guidelines was performed. The risk of bias of included trials was assessed. From 24 included RCTs, the following interventions increase uptake of faecal tests: advance notification letter (OR 1.20-1.51), postal mailing (OR 1.31-7.70), telephone contacts with an advisor (OR 1.36-7.72). Three interventions showed positive effects of GP involvement such as a GP-signed invitation letter [odds ratio (OR)=1.26], GP communication training (OR=1.22) or mailing reminders to GPs (OR=14.8). Inconclusive results were found for studies comparing different types of faecal tests and those testing the effectiveness of providing various types of written information. Advance notification letters, postal mailing of the faecal tests, written reminders and telephone contacts with an advisor increase patient uptake of faecal tests. There was only limited evidence on the effect of GP involvement on screening test uptake and a lack of studies focusing on nonresponders or disadvantaged groups.

Increasing participation in fecal screening tests is a major challenge in countries that have implemented colorectal cancer (CRC) screening programs.OBJECTIVE To determine whether providing general practitioners (GPs) a list of patients who are nonadherent to CRC screening enhances patient participation in fecal immunochemical testing (FIT). DESIGN, SETTING, AND PARTICIPANTSA 3-group, cluster-randomized study was conducted from July 14, 2015, to July 14, 2016, on the west coast of France, with GPs in 801 practices participating and involving adult patients (50-74 years) who were at average risk of CRC and not up-to-date with CRC screening. The final follow-up date was July 14, 2016.INTERVENTIONS General practitioners were randomly assigned to 1 of 3 groups: 496 received a list of patients who had not undergone CRC screening (patient-specific reminders group, 10 476 patients), 495 received a letter describing region-specific CRC screening adherence rates (generic reminders group, 10 606 patients), and 455 did not receive any reminders (usual care group, 10 147 patients). MAIN OUTCOMES AND MEASURESThe primary end point was patient participation in CRC screening 1 year after the intervention. RESULTS Among 1482 randomized GPs (mean age, 53.4 years; 576 women [38.9%]), 1446 participated; of the 33 044 patients of these GPs (mean age, 59.7 years; 17 949 women [54.3%]), follow-up at 1 year was available for 31 229 (94.5%). At 1 year, 24.8% (95% CI, 23.4%-26.2%) of patients in the specific reminders group, 21.7% (95% CI, 20.5%-22.8%) in the generic reminders group, and 20.6% (95% CI, 19.3%-21.8%) in the usual care group participated in the FIT screening. The between-group differences were 3.1% (95% CI, 1.3%-5.0%) for the patient-specific reminders group vs the generic reminders group, 4.2% (95% CI, 2.3%-6.2%) for the patient-specific reminders group vs the usual care group, and 1.1% (95% CI, −0.6% to 2.8%) for generic reminders group vs the usual care group. CONCLUSIONS AND RELEVANCEProviding French GPs caring for adults at average risk of CRC with a list of their patients who were not up-to-date with their CRC screening resulted in a small but significant increase in patient participation in FIT screening at 1 year compared with patients who received usual care. Providing GPs with generic reminders about regional rates of CRC screening did not increase screening rates compared with usual care.