Below is a flow diagram detailing the study design and the datasets available to request of MRC CFAS:
Although MRC CFAS is comprised of six centres across England and Wales, the core datasets described in the flow chart above are the data from the five centres which had identical sampling and interview structure (Cambridgeshire, Gwynedd, Newcastle, Nottingham and Oxford). Data for the Liverpool centre are treated separately and the study team can be contacted for more information if required.
During assessment interviews undertaken in 1997, blood or saliva samples were taken from 1,733 willing participants. Other blood samples have been taken from smaller subgroups of participants at various times during MRC CFAS leading the study to have a total of 2,670 samples stored.
The brain donation programme is managed locally within each CFAS centre. Individuals selected for assessment interviews were approached by a trained liaison officer who discussed the donation programmed with the respondent and his or her family or carers as appropriate. For those who were willing, a pre-mortem ‘Declaration of Intent’ (DOI) to donate their brain at autopsy was set up. When an individual dies the research team is notified and the next of kin is approached to give their consent for brain donation and retention. There have been over 580 successful donations to date with the programme still running.
The brains are dealt with according to local practices resulting in some variation between centres in the dissection, sampling and storage of brain tissues. Completed brain donations are subcategorised according to their status in the core study. The most informative donations are derived from respondents who entered the assessment phase and for whom there is sequential data on cognitive performance. The brain donor programme was set up to target this group as they had provided the most information during life.
CFAS interviewing data is stored within an anonymous data archive held on a secure server maintained by the Clinical School Computer Service at the University of Cambridge. Data is released in versions reflecting the additions of derived variables and follow up stage interview data. For MRC CFAS, the current version released to researchers is version 9.
In the interest of comparing data from MRC CFAS with the daughter study CFAS II, a subset of the MRC CFAS data (referred to as CFAS I) will be released which only contains the 3 geographical sites involved in both studies.
Researchers wishing to request CFAS data are encouraged to explore the website in formulating research ideas and questions. The data request form below should be completed and submitted to the National Coordinator in the first instance. Data applications are then reviewed by the Co-operative Management Committee (CMC) of CFAS before the Data Managers create the requested datasets for release.
Potential researchers should note that undertakings regarding stewardship and authorship of the data including the provision of returning the data back to the archive which must be agreed before any access to data is granted. A copy of the CFAS Authorship & Publication Policy is available. All researchers wishing to publish work using CFAS data must send drafts of papers to the National Coordinator prior to submission for circulation to the CMC for comments and feedback.
CFAS biological data is held at various locations around the country but is managed on behalf of the CFAS co-operative group by the CFAS tissue archive in Sheffield.
Researchers expressing an interest in accessing the biological resource data should complete the request forms below as appropriate and return to the National Coordinator. Potential researchers should note that proposals are put before the CMC and Biological Resource Advisory Committee (BRAC) for discussion and approval with sensitive proposals going before a sub-set of researchers as needed. Currently no linked data between the biological resource and the respondent data are released for general use. Blinding of data is undertaken at the CFAS Data Archive. Analysis of the linked data is undertaken within the secure server, where facilities exist for visiting workers. Proposals to access the tissue should therefore either provide funds for analysis or for workers to visit Cambridge.
Further information about the specific biological resources available in MRC CFAS can be found in the ‘MRC CFAS essential data section’ below.
Additional information regarding the datasets of MRC CFAS (5 centres) can be found in the following document available for download. Information is categorised in broad sections including variables which require further explanation, derived measurements along with further information of the biological resources and bolt on studies of MRC CFAS.
Along with the main study of MRC CFAS, there have been the following five linked studies.
• The Resource Implication Study (RIS) 1992 – 1994
Funded by the MRC for five years, this substudy was conducted by the Centre for Health Services Research Unit at Newcastle in collaboration with the Centre for Health Economics in York. The study involved collecting service use data over two years from MRC CFAS participants in Cambridge, Newcastle, Nottingham and Oxford. The data has allowed examination of carer burden and costs of care of physically and cognitively frail elderly people.
• The Network Study 1987 – 1994
Conducted within the Centre for Social Policy Research and Development at Bangor University with aims to describe the nature and distribution of support networks of elderly people and to examine the impact senile dementia has on these networks. Collaboration took place in Liverpool and Gwynedd with the project funded by DH/Welsh Office from June 1989 – May 1994.
• ESRC Healthy Ageing Project 1992 – 1993
This study aimed to explore the relationship between sociological, psychological and biological variables in a representative sample of the normal elderly population. This collaborative project ran between Cambridge and Nottingham and was funded by ESRC for a period of three years.
• Neuropathology and Neurology
A joint study of neuropathology has been undertaken at Oxford. The main purpose of this study is to diagnose different types of dementia through examination of tissue from the CFAS brain donation phase, relating the quantity of plaques and tangles with the degree of dementia. Collaboration taken place in the six MRC CFAS centres, separately funded for the first five years by the MRC. Subsequently this linked study was absorbed into the core CFAS activity and brain collection and examination is ongoing.
• Genetic Study
At the five year follow up interview of the assessed group of participants, requests were made to take and store blood or sputum samples for future analysis. Part of the MRC CFAS sample has had DNA extracted and genetic analyses conducted.
Please see the document in the ‘MRC CFAS essential data section’ for further details of the bolt-on studies.
Audit trail of MRC CFAS participants
The following two documents detail the flow of participants in MRC CFAS through the respondent and informant interview routes.
CFAS has been approved locally at all centres since its beginning in 1991. After the introduction of multi-centre research ethics committees, the study continued to apply for both multi-centre and local research ethics committee approval at each centre. The following document details the changes that have occurred over the previous 25 years to the title changes of local research ethics and multi-centre ethical committees, along with REC numbers.