Background: A previous randomized study found that verbal presentation of benefit of surgery in asymptomatic carotid stenosis expressed as qualitative or relative risk resulted in a higher proportion (66% versus 33%) of subjects choosing surgery as compared to subjects presented absolute risk, yearly risk, or event-free survival. Other variables that increased the choice of surgery were male gender, younger age, and higher level of education. Nevertheless, presentation format was the strongest predictor of treatment choice.