US national survey of physician practices for the secondary and tertiary prevention of ischemic stroke - Carotid endarterectomy

Background and Purpose Data from several randomized clinical trials concerning the efficacy of carotid endarterectomy (CE)in patients with symptomatic and asymptomatic stenoses of the extracranial carotid artery are now available. Yet, there are few data concerning the patterns of use of CE by physicians for their patients at risk for stroke. These data are critical for the rational allocation of resources and targeting of educational efforts. Methods Between August 1993 and February 1994, we surveyed the stroke prevention practices of a stratified random sample of 2000 US physicians. The survey queried the perceived availability and use of diagnostic studies and surgery for specific types of patients who might be considered candidates for CE. Results Of eligible physicians, 67% (n = 1006) completed the survey. Seventy percent reported that they always or often obtain carotid ultrasonography for evaluation of patients with asymptomatic bruits; 89% do so in patients with recent transient ischemic attack or minor stroke (P<.001). For asymptomatic patients, 13% always or often obtain a cerebral angiogram if carotid ultrasonography indicates 50% to 70% stenosis versus 33% if carotid ultrasonography indicates >70% stenosis (P<.001). For asymptomatic patients with >70% stenosis, a cerebral angiogram was reported as seldom or never used by 42% of physicians who viewed the test as readily available versus 67% if cerebral angiography was perceived as not readily available (P=.005). Multinomial multiple logistic regression analysis showed that symptom status, the degree of stenosis, perceived availability of CE, and physician specialty independently contributed to the explained variance in the reported use of CE (P<.001). The odds of performing CE were approximately four times greater in patients with recent symptoms compared with asymptomatic patients (P<.001) and four times greater in patients with >70% stenosis compared with patients with 50% to 70% stenosis (P<.001). Physicians who perceived CE as not being readily available were one third as likely to report using the procedure compared with physicians who reported having ready access (P=.004). CE was reported as being always or often used by more than 80% of neurologists and surgeons but by only about half of internists and noninternist primary care physicians for patients with newly symptomatic high-grade stenosis (P<.001). Almost one in four noninternist primary care physicians responded that they would seldom or never use CE for these patients. Conclusions These data show that (1) symptom status and degree of carotid artery stenosis strongly influence the reported frequency with which CE is used by practicing physicians; (2) the perceived availability of cerebral angiography and CE significantly affects their reported frequency of use; and (3) physician specialty significantly influences the reported frequency of use of CE.