Masking: Given the nature of the intervention, there's no masking of the health professionals or of the statistician responsible for the statistical analysis, but due to the objectivity of the final outcome we don't think the result could be influenced by this fact. Moreover the data manager for the CRC screening program, responsible for the data management of the participation outcome, does not know what study group the invited population was allocated to. Patients are also unaware of study group that they have been assigned to, and they have no access to the EMR.