USPSTF concluded with moderate certainty that the harms of screening for asymptomatic CAS outweigh the benefits.
Although carotid artery stenosis is a risk factor for stroke, only a relatively small proportion of strokes are caused by CAS, the task force noted. Adequate evidence does exist that ultrasound has high sensitivity and specificity for CAS; however, in practice, ultrasound "yields many false-positive results" in the general population, which has a CAS prevalence rate of approximately 0.5% to 1%. Furthermore, there are no validated and reliable tools that can determine who is at increased risk for stroke when CAS is present.
The task force also found no direct evidence of the benefits of screening for carotid artery stenosis, while concluding that there is adequate evidence that both the testing strategy for CAS and treatment with carotid endarterectomy can cause harms.
"Although screening with ultrasonography has few direct harms, all screening strategies, including those with or without confirmatory tests (i.e., digital subtraction or magnetic resonance angiography), have imperfect sensitivity and specificity and could lead to unnecessary interventions and result in serious harms," they wrote.
The draft statement is available for comment until March 17 at 5 p.m. EST.
Copyright © 2014 AuntMinnie.com