All 30,445 participants who consented to join the study were approached eighteen months later. They were sent an information sheet, providing a description of EPIC-Europe, and a progress report.

Participants were not seen at the 18 month follow-up, data was collected through postal questionnaires.

Questionnaires

• 7 day dietary diary (7dDD)
• Follow-up health and lifestyle questionnaire (HLQ)
• Health and life experiences questionnaire (HLEQ)

The eighteen-month gap between diaries was selected to record seasonal variations in diet. If participants responded to this, they were also sent a health and life experiences questionnaire (HLEQ), which was designed specifically for the EPIC-Norfolk study, to help understand influences and identify links between aspects of lives and health. The HLEQ includes questions about current and past health, as well as about experiences throughout life, and took between 45 minutes and 1 hour to complete.