Transient ischaemic attack, or TIA, occurs when there is interruption to the blood supply to the brain. Patients can have slurred speech, weakness on one side and problems with vision but symptoms resolve fully within 24 hours. The long-term outcome for patients following a TIA is not fully understood.
The TIA cohort study was carried out in the 1980s as part of the Oxford Community Stroke Project (OCSP) and an Oxford cohort study of hospital referred patients with TIA. The OCSP was a population-based study of the incidence of first ever TIA in a population of 105,000 people in Oxfordshire, UK, that ran from 1981 to 1986. The hospital referred cohort was recruited during the same period from patients referred from the remaining population of Oxfordshire that was not covered by the OCSP and included both first ever and recurrent TIA. Both studies involved a consecutive series of patients.
A total of 290 participants were recruited to the TIA cohort and their records were ‘flagged’ with the Office for National Statistics (ONS). This enables the study team to report who has died between the time of the study assessment and the present, and the date and cause of death.
The TIA cohort team, led by Professor Richard Hobbs and Dr Clare Taylor, is now based at the Nuffield Department of Primary Care Health Sciences at the University of Oxford. The team are currently working on TIA-Survive, a study exploring the long-term outcomes of the original study participants.
TIA-Survive continues to link the information provided by participants at study visits with NHS Digital and civil registration data to report the survival rates, and cause of death, for the whole cohort. This work will determine how long people live for following a diagnosis of TIA, and whether they die from stroke-related problems or something else, to help doctors and patients understand more about the condition.
The University of Oxford is the data controller. A minimum amount of identifiable data (name, date of birth, NHS number) is shared with NHS Digital to carry out the linkage between the study data and civil registration data. The data processor is also the University of Oxford. NHS Digital provide date and cause of death directly to the study team. As soon as the date and cause of death is linked with the participants study information, any data that could be used to directly identify individuals (name, date of birth, NHS number) is removed.
If you are a TIA cohort participant, you are free to withdraw your consent for data linkage with NHS Digital at any time.
Please contact the study team at firstname.lastname@example.org, call 01865 289300 or write to us at TIA cohort team, Nuffield Department of Primary Care Health Sciences, Radcliffe Primary Care Building, Woodstock Road, Oxford, OX2 6GG.