Underinvestigation and undertreatment of carotid disease in elderly patients with transient ischaemic attack and stroke: comparative population based study.

OBJECTIVE To identify any underinvestigation of older patients with transient ischaemic attack (TIA) and stroke. DESIGN Comparative population based studies. SETTING Routine clinical practice in all secondary care services in Oxfordshire and a nested population based study of incidence of transient ischaemic attack and stroke (the Oxford vascular study-OXVASC). PARTICIPANTS/POPULATION: All patients undergoing carotid imaging for ischaemic retinal or cerebral transient ischaemic attack or stroke from 1 April 2002 to 31 March 2005 in the Oxford vascular study (n = 91,105) and from 1 April 2002 to 31 March 2003 in routine clinical practice (n = 589,899). MAIN OUTCOME MEASURES Age specific rates of carotid imaging, diagnosed >or= 50% symptomatic carotid stenosis, and subsequent endarterectomy, in patients with recent transient ischaemic attack or stroke. RESULTS Of patients with recent carotid territory transient ischaemic attack or ischaemic stroke, 575 in routine clinical practice and 402 in the Oxford vascular study had carotid imaging, with similar rates up to the age of 80. The incidence of >or= 50% symptomatic stenosis increased steeply with age, particularly in those aged >or= 80. Compared with investigations in patients in the Oxford vascular study, the rates of carotid imaging (relative rate 0.36, 95% confidence interval 0.28 to 0.46, P < 0.0001), diagnosis of >or= 50% symptomatic stenosis (0.33, 0.16 to 0.69, P = 0.004), and carotid endarterectomy (0.19, 0.06 to 0.63, P = 0.007) in this age group in routine clinical practice were all substantially lower. CONCLUSIONS Incidence of symptomatic carotid stenosis increases steeply with age, but, despite good evidence of major benefit from endarterectomy in elderly patients and a willingness to have surgery, there is substantial underinvestigation in routine clinical practice in patients aged >or= 80 with transient ischaemic attack or ischaemic stroke.