Epidemiological aspects of referral to TIA clinics in Glasgow

A retrospective cohort study was carried out of new referrals to transient ischaemic attack (TIA) clinics in Glasgow. The aims of the study were to describe the profile of referrals and to assess the odds ratios for TIA, minor stroke or amaurosis fugax of both cardiovascular risk factors and clinical features. In total, data were collected for 813 new referrals in a period of six months. Thirteen point eight percent of referrals were from other Health Boards. The overall referral rate among residents of Greater Glasgow NHS Board was 165.6 per 100,000 per year. About 20% of referrals were made by clinicians in secondary care. The specialties from which referrals were most commonly made were accident and emergency, general medicine, ophthalmology and geriatric assessment. The most common risk factors in patients referred were hypertension (52.9%), smoking (31.7%), ischaemic heart disease (22.7%) and former smokers (22.4%). The most common clinical features were hemiparesis (13.3%), weakness of an upper limb (8.7%), vertigo (7.9%) and dysphasia (7.3%). In 48.7% of cases, a non-cerebrovascular diagnosis was made. Separate multivariate models were established for risk factors and clinical features. In the model for risk factors, five factors were significant for risk of TIA, stroke or amaurosis fugax. These were hyperlipidaemia, age over 64 years, hypertension, smoking and ex-smoking. In the model for clinical features, five factors were also significant. These were visual field defect, speech defact, facial weakness and hemiparesis.