Randomized Trial Evaluating the Effectiveness of the General Practitioner Involvement in Cancer Screening Invitations

Our goal is to evaluate, in France, the effectiveness (in terms of participation) of the general practitioner involvement (signature) and a more personalized communication in invitation letters to organized screening of breast, colorectal and cervical cancers.
The hypothesis on which this project is based is that communication is probably more effective if the "receiver" feels personally targeted by invitation letters (Dear Martin, I am writing ...) and if he knows "the issuer "(his general practitioner rather an unknown person).