Diagnosis and Management of Transient Ischaemic Attack in Primary Care

Background:

Most patients with Transient Ischaemic Attack (TIA) present to their general practitioner (GP). Early identification and specialist assessment reduces the risk of subsequent stroke and mortality.

Aim:

To examine the diagnosis and immediate management of suspected TIA in primary care, and to evaluate the performance of a diagnostic tool (Dawson score) for TIA to guide GPs’ referral decisions and to triage clinic referrals.

Design and setting:

A mixed methods approach was taken, incorporating three inter-related studies. Firstly, a systematic review on the diagnosis and management of TIA. Secondly, an external validation of the Dawson score at a TIA clinic in the midlands of England. Thirdly, a qualitative study, involving 10 GP telephone interviews to explore their views of TIA, and the potential of a diagnostic tool. A further exploratory study looked into alternative cut-offs for the Dawson score in response to GPs’ suggestions, and derived a logistic regression model to estimate risk of TIA.

Results:

The review found limitations in GPs’ ability to diagnose TIAs and demonstrated the potential for a diagnostic tool to enhance referral patterns. The external validation study concluded that the diagnostic tool could be used alongside GPs’ clinical judgement to reduce the number of non-cerebrovascular referrals to the TIA clinic. GPs reported that TIA was likely to be suspected in obvious TIA candidates, and referrals were a strategy to eliminate uncertainty whilst seeking reassurance. A diagnostic tool for TIA could improve the decisionmaking process and enhance GP confidence. Further analyses concluded that GPs’ desired risk percentages combined with clinical judgement may be more useful than cut-offs.

Conclusions:

The thesis demonstrated the complexity of GPs’ TIA diagnostic and referral decisions, and supported the value of a diagnostic tool. Further work directed towards using primary care data to further develop and implement a diagnostic tool is recommended.