Cost-Effectiveness of a Specialized Ultrasound Instrument to Diagnose Carotid Stenosis as a Way to Reduce the Risk of Stroke

Stroke is the third leading cause of death, and the leading cause of long-term disability in
the United States. At least half of all strokes are caused by carotid stenosis, a condition
in which the arteries in the neck become blocked with plaque and harden. Plaque that breaks
off the carotid artery wall and travels to the brain can block critical blood vessels,
possibly resulting in a stroke. Carotid endarterectomy, a procedure that removes plaque
buildup, can greatly reduce an individual's risk for stroke. Currently, the conventional
duplex Doppler ultrasound examination that is used to screen for carotid stenosis requires a
skilled sonographer or physician, and is therefore expensive. Study researchers have
developed a more cost-effective option: a specialized ultrasound instrument specifically
designed to perform carotid stenosis screenings and meant to be used by non-specialist
nurses. Previous research has shown that this instrument is inexpensive, easy to use, and
effective at diagnosing carotid stenosis. The purpose of this study is to evaluate the
cost-effectiveness of the alternative ultrasound instrument at screening older adults who
are at risk for carotid stenosis. If the instrument is shown to be cost-effective, it may
eventually lead to widespread screening and a reduced incidence of stroke.

In this study, nurses in selected physician's offices will be trained to use the carotid
ultrasound screening instrument. Patients over 65 years of age with at least one risk factor
for carotid stenosis but with no symptoms will be screened with the device. Screening will
take place in the doctors' offices or, when more convenient, at a central screening
location; however, in all cases the nurses will use the instrument rather than specialized
ultrasound technologists. Individuals found to have carotid stenosis will be referred to
undergo a conventional duplex Doppler ultrasound examination for a definitive diagnosis.

Inclusion Criteria:

- At least one risk factor for carotid stenosis (e.g., cardiac disease, elevated
cholesterol, smoking, hypertension)

Exclusion Criteria:

- Any symptoms or indications of carotid stenosis or stroke