Frequently Asked Questions
Here are the answers to the most common questions which we are asked about the EPIC-Oxford study.
Do you need any more volunteers?
No, the recruitment process for EPIC-Oxford is completed, so we do not need any more participants. Follow-up questionnaires have been sent out to people who completed an original recruitment questionnaire approximately 5, 10 and 15 years later. The last follow-up questionnaire was sent out in autumn 2010.
Can I withdraw from the study?
Yes, you are free to withdraw from EPIC-Oxford or the Oxford Vegetarian Study (OVS) at any time. Please let us know in writing to:
EPIC-Oxford/Oxford Vegetarian Study
Cancer Epidemiology Unit
Nuffield Department of Population Health
Richard Doll Building
Oxford OX3 7LF
Tel: Office hours (01865) 289600
It is helpful if you can let us know which study you wish to withdraw from e.g. EPIC-Oxford or OVS or both and which of these three options you prefer:
1. No further contact
We will no longer contact you, but you give us permission to keep and continue to use information (and any blood samples) you have already provided, and to continue to obtain and use information from your medical records to follow your health, as before, including the sharing of identifiable data including your name with NHS Digital, NRS Scotland and PEDW Wales to obtain data from your medical record.
2. No further contact or access to your health records
We will not contact you again and we will not collect any more information through your health records; but you give us permission to keep and use the information (and any samples) already provided.
3. Complete withdrawal (no further use of data)
In addition to no longer contacting you or obtaining information through medical records, we will stop new use of the information and of samples already provided (your information may be included in anonymised datasets already being analysed and it may not be possible to remove your data from these, but we will ensure that your information is not used in future).
Is your sample representative of the general population?
No, the strategy for establishing the EPIC-Oxford cohort was to recruit people with a wide range of diets by targeting vegetarians as well as the general UK population. 50% of our sample have a meat-free diet. This is extremely valuable, because it is the largest study of vegetarians in the world with linkage to comprehensive health records and will provide extensive information on the long-term health of vegetarians.
Do you use animals in your research?
No, the EPIC study provides an ideal opportunity for research on humans. Furthermore the Oxford component of EPIC includes 27,000 participants who do not eat meat, of which 24,987 are vegetarian and 2,162 are vegan.
Will my name and address be passed on to any other organisations?
No, the information you provide on your diet, lifestyle and health is known only to the research group involved in the EPIC-Oxford study and will be used only for medical research. Your name and address are used by the study investigators, in order to contact you personally. In addition, identifiable data including your name is supplied by the study investigators to NHS Digital, PedW Wales and NRS Scotland to enable us to obtain data from your medical records. All data is handled and held under appropriate secure conditions, and is used anonymously for all analyses. EPIC-Oxford is registered under the Data Protection Act and has received ethics approval from the relevant authority.
Can you give me any individual results?
No, data are analysed anonymously, so unfortunately we are unable to give feedback on an individual basis. The analyses we conduct are designed to explore the associations with the health of groups of people, but would not be expected to be of much relevance to individual participants.
What should I do if I change address?
Please let us know your change of address so that we can update our records. You can contact us by email firstname.lastname@example.org or by telephone on 01865 289600.
Suggested Further FAQs (following NHS Digital approval of removal of CAG approval for data processing)
I plan to emigrate. Will I still be included in the EPIC-Oxford study?
If you plan to live abroad, please let us know so that we can update our records and ensure that no further correspondence is sent to your old address. If you plan to return to the UK in the future, and are still willing to participate in the EPIC-Oxford study, please inform us of your new UK address on your return.
What does the future hold for EPIC-Oxford?
With its long follow-up, EPIC-Oxford is now a very rich source of data and we have a programme of analyses planned for the next few years on the relationships of diet and other factors with the risks for cancer and other diseases. EPIC-Oxford is currently funded by Cancer Research UK and Wellcome, with support until 2025, after which we hope to obtain further funding from new grants.
What permission do you have to use my data for research?
When participants joined the EPIC-Oxford Study between 1993 and 1999 informed consent was given by each participant to allow the study to access their medical records for research purposes only.
Soon after the recruitment of participants, using this consent, identification details of participants were provided to the Office of National Statistics to collect cancer and death information for participants for our research.
The consent given at recruitment was also used in subsequent years to obtain information from these NHS health data providers:
- NHS Digital - Mortality data and cancer diagnoses in England and Wales
- National Records for Scotland (NRS) - all hospital admissions, mortality data, cancer diagnoses in Scotland
- Patient Episode Database for Wales (PedW) - all hospital admissions in Wales
- Public Health England (PHE) – Information on cancer diagnoses and treatment (part of NHS Digital from October 2021).
- NHS Trusts – pathology reports and other information not obtainable via data providers.
In 2008, a mistake was made in our application to request Hospital Admission Records (Hospital Episode Statistics data) for participants in England. The existing consent for access to medical records was not used for the legal basis, and instead an application was made to collect the hospital admission records about participants in England using Section 251 of the National Health Service Act 2006, which waives the requirement for consent, and provides an alternative legal basis for collecting this information. This was approved by the Confidentiality Advisory Group in 2008, and again in 2015. The use of Section 251 in EPIC-Oxford has only been for participants in England, all linkage to NHS Scotland and NHS data for Wales has been conducted under consent throughout the study follow-up since 1993.
When section 251 is used as a legal basis to collect information about individuals in a study, any participants who registered with the NHS for their health records not to be shared for research and planning (“opted out”) have this opting out choice applied to the health information provided by the NHS to EPIC-Oxford. Consequently this reduces the numbers of EPIC-Oxford participants reported to the study as being diagnosed with illnesses during their life. This information is collected from Hospital Episode Statistics (HES) Data provided by NHS Digital. This causes a disparity between the deaths and cancer data (where all occurrences are provided under the legal basis of consent) and the Hospital Episode Statistics data provided to EPIC-Oxford, which may bias the results. Therefore changing the legal basis for HES data to be received under the legal basis of consent will improve the quality of our research.
The EPIC-Oxford researchers have applied to both CAG and NHS Digital to ask for the Section 251 status to be removed and to be able instead to collect the hospital information data for England using consent as the legal basis. CAG advised that NHS Digital should review this because they are the data provider.
This has now been reviewed and the independent committee that oversees the data releases from NHS Digital (IGARD) has agreed that the legal basis of consent can be used to obtain the Hospital data for EPIC-Oxford participants in England.
This change in processing participants’ data has also been discussed in an EPIC- Oxford participant panel meeting where it was agreed by participants that the consent given to access medical records at enrolment into the study was understood by the participants to apply to all medical records, including hospital records from England.
We would like to make it clear that if a participant is not happy with this decision or wishes to opt-out of the EPIC-Oxford study then they should inform us in writing (see ‘Can I withdraw from the study?’ for address) and we will ensure that their data are no longer used in our research.