Participants will be invited to complete the first follow-up questionnaire via email from early 2019. Invitations will be sent out on a rolling basis over the next 4 to 5 years, based on when the original study was completed (submission of questionnaires and saliva sample). We aim to keep the follow up questionnaire brief. It will be completed online.
Please let us know if your contact details change so we can keep in touch about future follow-ups.