The NICOLA Recruitment Trial (NICOLA-RT)

"There are 12 versions of the invitation letter. Three aspects of the letter will be adapted: (1) Gender of the signatory i.e. male, female or gender neutral (signed from the NICOLA team) (2) Description of NICOLA as a 'study' or 'project' and (3) Inserting a sentence guaranteeing the participants confidentially or not having this in the letter (but will still appear in the Patient Information Sheet). The twelve versions are as follows:~1. Male \& Study \& Confidentiality~2. Male \& Study~3. Male \& Project \& Confidentiality~4. Male \& Project~5. Female \& Project \& Confidentiality~6. Female \& Project~7. Female \& Study \& Confidentiality~8. Female \& Study~9. Neutral \& Study \& Confidentiality~10. Neutral \& Study~11. Neutral \& Project \& Confidentiality~12. Neutral \& Project"