Viewing Readiness-for-Residency through Binoculars: Mapping Competency-Based Assessments to the AAMC's 13 Core Entrustable Professional Activities (EPAs).

Construct: The construct being assessed is readiness-for-residency of graduating medical students, as measured through two assessment frameworks. Background: Readiness-for-residency of near-graduate medical students should be but is not consistently assessed. To address this, the Association of American Medical Colleges (AAMC), in 2014, identified and described 13 core Entrustable Professional Activities (EPAs), which are tasks that all residents should be able to perform unsupervised upon entering residency. However, the AAMC did not initially provide measurement guidelines or propose standardized assessments. We designed Night-onCall (NOC), an immersive simulation for our near-graduating medical students to assess and address their readiness-for-residency, framed around tasks suggested by the AAMC's core EPAs. In adopting this EPA assessment framework, we began by building upon an established program of competency-based clinical skills assessments, repurposing competency-based checklists to measure components of the EPAs where possible, and designing new checklists, when necessary. This resulted in a blended suite of 14 checklists, which theoretically provide substantive assessment of all 13 core EPAs. In this paper, we describe the consensus-based mapping process conducted to ensure we understood the relationship between competency and EPA-based assessment lenses and could therefore report meaningful feedback on both to transitioning students in the NOC exercise. Approach: Between January-November 2017, five clinician and two non-clinician health professions educators at NYU Grossman School of Medicine conducted a rigorous consensus-based mapping process, which included each rater mapping each of the 310 NOC competency-based checklist items to lists of entrustable behaviors expected of learners according to the AAMC 13 core EPAs. Findings: All EPAs were captured to varying degrees by the 14 NOC checklists (overall Intraclass Correlation Coefficient (ICC) = 0.77). Consensus meetings resolved discrepancies and improved ICC values for three (EPA-9, EPA-10, EPA-12) of the four EPAs that initially showed poor reliability. Conclusions: Findings suggest that with some limitations (e.g., EPA-7 "form clinical questions/retrieve evidence") established competency-based assessments can be repurposed to measure readiness-for-residency through an EPA lens and both can be reported to learners and faculty.

Comparison of Recent Practice Guidelines for the Management of Patients With Asymptomatic Carotid Stenosis.

Despite the publication of several national/international guidelines, the optimal management of patients with asymptomatic carotid stenosis (AsxCS) remains controversial. This article compares 3 recently released guidelines (the 2020 German-Austrian, the 2021 European Stroke Organization [ESO], and the 2021 Society for Vascular Surgery [SVS] guidelines) vs the 2017 European Society for Vascular Surgery (ESVS) guidelines regarding the optimal management of AsxCS patients.The 2017 ESVS guidelines defined specific imaging/clinical parameters that may identify patient subgroups at high future stroke risk and recommended that carotid endarterectomy (CEA) should or carotid artery stenting (CAS) may be considered for these individuals. The 2020 German-Austrian guidelines provided similar recommendations with the 2017 ESVS Guidelines. The 2021 ESO Guidelines also recommended CEA for AsxCS patients at high risk for stroke on best medical treatment (BMT), but recommended against routine use of CAS in these patients. Finally, the SVS guidelines provided a strong recommendation for CEA+BMT vs BMT alone for low-surgical risk patients with >70% AsxCS. Thus, the ESVS, German-Austrian, and ESO guidelines concurred that all AsxCS patients should receive risk factor modification and BMT, but CEA should or CAS may also be considered for certain AsxCS patient subgroups at high risk for future ipsilateral ischemic stroke.

Optimal Management of Asymptomatic Carotid Stenosis in 2021: The Jury is Still Out. An International, Multispecialty, Expert Review and Position Statement.

OBJECTIVES: The recommendations of international guidelines for the management of asymptomatic carotid stenosis (ACS) often vary considerably and extend from a conservative approach with risk factor modification and best medical treatment (BMT) alone, to a more aggressive approach with a carotid intervention plus BMT. The aim of the current multispecialty position statement is to reconcile the conflicting views on the topic. MATERIALS AND METHODS: A literature review was performed with a focus on data from recent studies. RESULTS: Several clinical and imaging high-risk features have been identified that are associated with an increased long-term ipsilateral ischemic stroke risk in patients with ACS. Such high-risk clinical/imaging features include intraplaque hemorrhage, impaired cerebrovascular reserve, carotid plaque echolucency/ulceration/ neovascularization, a lipid-rich necrotic core, a thin or ruptured fibrous cap, silent brain infarction, a contralateral transient ischemic attack/stroke episode, male patients < 75 years and microembolic signals on transcranial Doppler. There is growing evidence that 80-99% ACS indicate a higher stroke risk than 50-79% stenoses. CONCLUSIONS: Although aggressive risk factor control and BMT should be implemented in all ACS patients, several high-risk features that may increase the risk of a future cerebrovascular event are now documented. Consequently, some guidelines recommend a prophylactic carotid intervention in high-risk patients to prevent future cerebrovascular events. Until the results of the much-anticipated randomized controlled trials emerge, the jury is still out regarding the optimal management of ACS patients.

Optimal management of asymptomatic carotid stenosis in 2021: the jury is still out. An international, multispecialty, expert review and position statement.

The recommendations of international guidelines for the management of asymptomatic carotid stenosis (ACS) often vary considerably and extend from a conservative approach with risk factor modification and best medical treatment (BMT) alone, to a more aggressive approach with a carotid intervention plus BMT. The aim of the current multispecialty position statement was to reconcile the conflicting views on the topic. A literature review was performed with a focus on data from recent studies. Several clinical and imaging high-risk features have been identified that are associated with an increased long-term ipsilateral ischemic stroke risk in patients with ACS. Such high-risk clinical/imaging features include intraplaque hemorrhage, impaired cerebrovascular reserve, carotid plaque echolucency/ulceration/ neovascularization, a lipid-rich necrotic core, a thin or ruptured fibrous cap, silent brain infarction, a contralateral transient ischemic attack/stroke episode, male patients <75 years and microembolic signals on transcranial Doppler. There is growing evidence that 80-99% ACS indicate a higher stroke risk than 50-79% stenoses. Although aggressive risk factor control and BMT should be implemented in all ACS patients, several high-risk features that may increase the risk of a future cerebrovascular event are now documented. Consequently, some guidelines recommend a prophylactic carotid intervention in high-risk patients to prevent future cerebrovascular events. Until the results of the much-anticipated randomized controlled trials emerge, the jury is still out regarding the optimal management of ACS patients.

Improving the Clinical Skills Performance of Graduating Medical Students Using "WISE OnCall," a Multimedia Educational Module.

INTRODUCTION: "Transitions to residency" programs are designed to maximize quality and safety of patient care, as medical students become residents. However, best instructional or readiness assessment practices are not yet established. We sought to study the impact of a screen-based interactive curriculum designed to prepare interns to address common clinical coverage issues (WISE OnCall) on the clinical skills demonstrated in simulation and hypothesize that performance would improve after completing the module. METHODS: Senior medical students were recruited to participate in this single group prestudy/poststudy. Students responded to a call from a standardized nurse (SN) and assessed a standardized patient (SP) with low urine output, interacted with a 45-minute WISE OnCall module on the assessment and management of oliguria, and then evaluated a different SP with low urine output of a different underlying cause. Standardized patients assessed clinical skills with a 37-item, behaviorally anchored checklist measuring clinical skills (intraclass correlation coefficient [ICC], 0.55-0.81). Standardized nurses rated care quality and safety and collaboration and interprofessional communication using a 33-item literature-based, anchored checklist (ICC, 0.47-0.52). Standardized patient and SN ratings of the same student performance were correlated (r, 0.37-0.62; P < 0.01). Physicians assessed clinical reasoning quality based on the students' patient encounter note (ICC, 0.55-0.68), ratings that did not correlate with SP and SN ratings. We compared pre-post clinical skills performance and clinical reasoning. Fifty-two medical students (31%) completed this institutional review board -approved study. RESULTS: Performance as measured by the SPs, SNs, and the postencounter note all showed improvement with mostly moderate to large effect sizes (range of Cohen's d, 0.30-1.88; P < 0.05) after completion of the online module. Unexpectedly, professionalism as rated by the SP was poorer after the module (Cohen's d, -0.93; P = 0.000). DISCUSSION: A brief computer-based educational intervention significantly improved graduating medical students' clinical skills needed to be ready for residency.

The Impact of Oral-Systemic Health on Advancing Interprofessional Education Outcomes.

The aim of this study was to evaluate the effectiveness of an interprofessional education (IPE) clinical simulation and case study experience, using oral-systemic health as the clinical population health example, for nurse practitioner/midwifery, dental, and medical students' self-reported attainment of interprofessional competencies. A pretest-posttest evaluation method was employed, using data from the Interprofessional Collaborative Competency Attainment Scale (ICCAS) completed by two large cohorts of nurse practitioner/midwifery, dental, and medical students at one U.S. university. Data from faculty facilitators were collected to assess their perceptions of the value of exposing students to interprofessional clinical simulation experiences focused on oral-systemic health. The results showed that self-reported interprofessional competencies measured by the ICCAS improved significantly from pre- to posttest for all three student types in 2013 (p<0.001) and 2014 (p<0.001). Faculty facilitators reported that the IPE clinical simulation experiences were valuable and positively influenced interprofessional communication, collaboration, patient communication, and student understanding of patient care roles. These results suggest that the Teaching Oral-Systemic Health Program Interprofessional Oral-Systemic Health Clinical Simulation and Case Study Experience was effective as a standardized, replicable curriculum unit using oral-systemic health as a population health exemplar to teach and assess interprofessional competencies with nurse practitioner/midwifery, dental, and medical students.

A simulated "Night-onCall" to assess and address the readiness-for-internship of transitioning medical students.

Transitioning medical students are anxious about their readiness-for-internship, as are their residency program directors and teaching hospital leadership responsible for care quality and patient safety. A readiness-for-internship assessment program could contribute to ensuring optimal quality and safety and be a key element in implementing competency-based, time-variable medical education. In this paper, we describe the development of the Night-onCall program (NOC), a 4-h readiness-for-internship multi-instructional method simulation event. NOC was designed and implemented over the course of 3 years to provide an authentic "night on call" experience for near graduating students and build measurements of students' readiness for this transition framed by the Association of American Medical College's Core Entrustable Professional Activities for Entering Residency. The NOC is a product of a program of research focused on questions related to enabling individualized pathways through medical training. The lessons learned and modifications made to create a feasible, acceptable, flexible, and educationally rich NOC are shared to inform the discussion about transition to residency curriculum and best practices regarding educational handoffs from undergraduate to graduate education.

Co-existence of vascular disease in different arterial beds: Peripheral artery disease and carotid artery stenosis--Data from Life Line Screening(®).

BACKGROUND: Atherosclerosis is a systemic vascular disorder, involving multiple arterial territories. This project sought to investigate the relationship between lower extremity peripheral artery disease (PAD) and carotid artery stenosis (CAS) in a large self-referred population. METHODS: Data from the ankle brachial index (ABI) and carotid duplex ultrasound were analyzed from 3.67 million US subjects in the Life Line Screening program between 2004 and 2008. PAD was defined by ABI<0.9 and CAS was defined by greater than 50% stenosis. Multivariate logistic regression analysis was used to estimate odds of CAS by PAD status and severity. RESULTS: Mean age of the population was 63.7 ± 10.6 years and 64% were women. The prevalence of PAD and CAS was 4.1% and 3.9%, respectively. Subjects with PAD had a higher prevalence of CAS than those without PAD (18.8% vs. 3.3%, P < 0.0001). In multivariate analysis, PAD was associated with greater odds of CAS (OR 3.28, 95% CI 3.22-3.34). Both symptomatic (OR 3.66, 95% CI 3.58-3.75) and asymptomatic PAD (OR 2.91, 95% CI 2.84-2.98) was associated with CAS. Increasing severity of PAD was associated with greater odds of CAS (OR 2.32, 3.61, 4.19, 5.14, and 7.59 for ABI categories 0.81-0.90, 0.71-0.80, 0.61-0.70, 0.41-0.60, ≤0.40, respectively). CONCLUSION: Presence and severity of PAD was associated with prevalence of CAS in the large self-referred and self-paying Life Line cohort, regardless of lower extremity symptoms.

Association between physical activity and peripheral artery disease and carotid artery stenosis in a self-referred population of 3 million adults.

OBJECTIVE: Although the relationship between physical activity and coronary heart disease is well characterized, a paucity of data exists on physical activity and vascular disease in other arterial territories. This study examined the prevalence of peripheral artery disease (PAD) and carotid artery stenosis (CAS) in association with physical activity. APPROACH AND RESULTS: The association between physical activity and vascular disease was examined in >3 million self-referred US participants in the United States from 2003 to 2008 who completed a medical and lifestyle questionnaire in the Life Line screening program. All subjects were evaluated by screening ankle brachial indices <0.90 for PAD and ultrasound imaging for CAS >50%. Multivariable logistic regression modeling was used to estimate odds of disease. Among 3 250 350 subjects, 63% of the population engaged in some leisure time vigorous physical activity. After adjustment for age, sex, race/ethnicity, hypertension, hypercholesterolemia, smoking status, diabetes mellitus, body mass index, and family history of cardiovascular disease, subjects who reported any physical activity had a significantly lower odds of PAD (odds ratio, 0.64; 95% confidence interval, 0.63-0.65) and CAS (odds ratio, 0.80; 95% confidence interval, 0.79-0.81). The association between physical activity with PAD and CAS was robust when stratified by sex, race, and age categories. Physical activity intensity frequency was associated with lower PAD and CAS in a graded manner (P trend <0.0001 for both). Findings seemed unaffected by confounding by comorbidity or indication. CONCLUSIONS: In a large population-based study, higher levels of physical activity were independently associated with lower odds of vascular disease in the lower extremities and carotid arteries.

Diabetes and vascular disease in different arterial territories.

OBJECTIVE: The aim of this study was to investigate the relationship between diabetes and different phenotypes of peripheral vascular disease (lower extremity peripheral artery disease [PAD], carotid artery stenosis [CAS], and abdominal aortic aneurysm [AAA]). RESEARCH DESIGN AND METHODS: Prevalence of vascular disease was evaluated in 3,696,778 participants of the Life Line Screening survey between 2003 and 2008. PAD was defined as ankle-brachial pressure index <0.90 or prior revascularization, CAS as ≥50% stenosis or prior revascularization, and AAA as infrarenal aortic diameter ≥3 cm or prior repair. Odds ratios (ORs) and 95% CIs were assessed using logistic regression modeling. RESULTS: Diabetes mellitus was present in 10.8% of participants (n = 399,884). Prevalence of PAD, CAS, and AAA was significantly higher (P < 0.0001) in participants with compared with those without diabetes. After multivariate adjustment for baseline demographics and clinical risk factors, a significant interaction existed between diabetes and vascular disease phenotype (P < 0.0001). Diabetes was associated with increased odds of PAD (OR 1.42 [95% CI 1.41-1.4]; P < 0.0001) and CAS (1.45 [1.43-1.47]; P < 0.0001) but decreased odds of AAA (0.86 [0.84-0.88]; P < 0.0001). The strength of association increased with increasing severity of disease in each vascular phenotype, and this association persisted in the population with asymptomatic vascular disease. CONCLUSIONS: In a large population-based study, the association between diabetes and vascular disease differed according to vascular phenotype. Future studies exploring the mechanism for these vascular-specific differences are needed.

Association of the ankle-brachial index with history of myocardial infarction and stroke.

BACKGROUND: Ankle-brachial index (ABI) testing is a simple, noninvasive method to diagnose peripheral artery disease (PAD) and is associated with all-cause mortality. The association of ABI levels and myocardial infarction (MI) and stroke is less certain. We sought to further characterize the association between ABI levels and history of MI and stroke. METHODS: Using data from the Life Line Screening program, 3.6 million self-referred participants from 2003 to 2008 completed a medical questionnaire and had bilateral ABIs performed. Logistic regression was used to estimate the association between ABI cutoff points (ABI <0.90 and ABI >1.40) and ABI levels with history of MI, stroke, and MI or stroke (MI/stroke). Models were adjusted for age, sex, race/ethnicity, smoking, diabetes, hypertension, hypercholesterolemia, physical activity, and family history of cardiovascular disease. Separate sex-specific models were performed. RESULTS: Overall, 155,552 (4.5%) had an ABI <0.90, and 42,890 (1.2%) had an ABI >1.40. An ABI <0.90 was associated with higher odds of MI (adjusted odds ratio [OR] 1.67, 95% CI 1.63-1.71), stroke (OR 1.77, 95% CI 1.72-1.82), and MI/stroke (OR 1.71, 95% CI 1.67-1.74), all P < .001. An ABI >1.40 was also associated with higher odds of MI (OR 1.19, 95% CI 1.14-1.24), stroke (OR 1.30, 95% CI 1.22-1.38), and MI/stroke (OR 1.22, 95% CI 1.17-1.27), all P < .001. The ORs for MI/stroke for different ABI levels formed a reverse J-shaped curve in both women and men. CONCLUSIONS: In a large national screening database, there is a strong, consistent relationship between ABI levels and a history of prevalent MI, stroke, and MI/stroke.

Concomitant unruptured intracranial aneurysms and carotid artery stenosis: an institutional review of patients undergoing carotid revascularization.

BACKGROUND: The incidence of concomitant carotid artery stenosis and unruptured intracranial aneurysms (UIAs) has been reported at between 0.5% and 5%. In these patients, treatment strategies must balance the risk of ischemic stroke with the risk of aneurysmal rupture. Several studies have addressed the natural course of UIAs in the setting of carotid revascularization; however, the final recommendations are not uniform. The purpose of this study was to review our institutional experience with concomitant UIAs and carotid artery stenosis. METHODS: We performed a retrospective review of all patients with carotid artery stenosis who underwent carotid artery endarterectomy (CEA) or carotid artery stenting (CAS) at our institution between 2003 and 2010. Only patients with preoperative imaging demonstrating intracranial circulation were included. Charts were reviewed for patients' demographic and clinical data, duration of follow-up, and aneurysm size and location. Patients were stratified into 2 groups: carotid artery stenosis with unruptured intracranial aneurysm (CS/UIA) and carotid artery stenosis without intracranial aneurysm (CS). RESULTS: Three hundred five patients met the inclusion criteria and had a total of 316 carotid procedures (CAS or CEA) performed. Eleven patients were found to have UIAs (3.61%) prior to carotid revascularization. Male and female prevalence was 2.59% and 5.26% (P = 0.22), respectively. Patients' demographics did not differ significantly between the 2 groups. The average aneurysm size was 3.25 ± 2.13 mm, and the most common location was the cavernous segment of the internal carotid artery. No patient in the study had aneurysm rupture, and the mean follow-up time was 26.5 months for the CS/UIA group. CONCLUSIONS: Concomitant carotid artery stenosis and UIAs is a rare entity. Carotid revascularization does not appear to increase the risk of rupture for small aneurysms (<10 mm) in the midterm. Although not statistically significant, there was a higher incidence of aneurysms found in females in our patient population.

Modifiable risk factor burden and the prevalence of peripheral artery disease in different vascular territories.

BACKGROUND: The precise relationship between risk factor burden and prevalence of peripheral artery disease (PAD) in different vascular territories (PAD, carotid artery stenosis [CAS], and abdominal aortic aneurysms [AAAs]) is unclear. METHODS: We investigated the association of modifiable risk factors (hypertension, hypercholesterolemia, smoking, diabetes, and sedentary lifestyle) with any and type-specific peripheral vascular disease (PVD) among 3.3 million patients in the U.S., aged 40 to 99, who underwent screening bilateral ankle brachial indices, carotid duplex ultrasound, and abdominal aortic ultrasound in the Life Line Screening program between 2004 and 2008. Multivariate logistic regression analysis was used to estimate the odds of disease in different risk factor categories. Population-attributable risk was calculated to estimate the proportion of disease that could be potentially ascribed to modifiable risk factors. RESULTS: Among 3,319,993 participants, prevalence of any PVD was 7.51% (95% confidence interval [CI], 7.50%-7.53%). PAD was present in 3.56% (95% CI, 3.54%-3.58%), CAS in 3.94% (95% CI, 3.92%-3.96%), and AAAs in 0.88% (95% CI, 0.86%-0.89%). The multivariate-adjusted prevalence with the presence of 0, 1, 2, 3, 4, and 5 modifiable risk factors was 2.76, 4.63, 7.12, 10.73, 16.00, and 22.08 (P < .0001 for trend) for any PVD; 1.18, 2.09, 3.28, 5.14, 8.32, and 12.43 (P < .0001 for trend) for PAD; 1.41, 2.36, 3.72, 5.73, 8.48, and 11.58 (P < .0001 for trend) for CAS; and 0.31, 0.54, 0.85, 1.28, 1.82, and 2.39 (P < .0001 for trend) for AAAs, respectively. These associations were similar for men and women. For every additional modifiable risk factor that was present, the multivariate-adjusted odds of having vascular disease increased significantly (any PVD [odds ratio (OR), 1.58; 95% CI, 1.58-1.59]; PAD [OR, 1.62; 95% CI, 1.62-1.63]; CAS [OR, 1.57; 95% CI, 1.56-1.57]; and AAA [OR, 1.51; 95% CI, 1.50-1.53]). CONCLUSIONS: This very large contemporary database demonstrates that risk factor burden is associated with an increased prevalence of PVD, and there is a graded association between the number of risk factors present and the prevalence of PAD, CAS, and AAAs.

Association between advanced age and vascular disease in different arterial territories: a population database of over 3.6 million subjects.

OBJECTIVES: This study sought to determine the relationship between vascular disease in different arterial territories and advanced age. BACKGROUND: Vascular disease in the peripheral circulation is associated with significant morbidity and mortality. There is little data to assess the prevalence of different phenotypes of vascular disease in the very elderly. METHODS: Over 3.6 million self-referred participants from 2003 to 2008 who completed a medical and lifestyle questionnaire in the United States were evaluated by screening ankle brachial indices <0.9 for peripheral artery disease (PAD), and ultrasound imaging for carotid artery stenosis (CAS) >50% and abdominal aortic aneurysm (AAA) >3 cm. Participants were stratified by decade of life. Multivariate logistic regression analysis was used to estimate odds of disease in different age categories. RESULTS: Overall, the prevalence of PAD, CAS, and AAA, was 3.7%, 3.9%, and 0.9%, respectively. Prevalence of any vascular disease increased with age (40 to 50 years: 2%, 51 to 60 years: 3.5%, 61 to 70 years: 7.1%, 71 to 80 years: 13.0%, 81 to 90 years: 22.3%, 91 to 100 years: 32.5%; p < 0.0001). Prevalence of disease in each vascular territory increased with age. After adjustment for sex, race/ethnicity, body mass index, family history of cardiovascular disease, smoking, diabetes, hypertension, hypercholesterolemia, and exercise, the odds of PAD (odds ratio [OR]: 2.14; 95% confidence interval [CI]: 2.12 to 2.15), CAS (OR: 1.80; 95% CI: 1.79 to 1.81), and AAA (OR: 2.33; 95% CI: 2.30 to 2.36) increased with every decade of life. CONCLUSIONS: There is a dramatic increase in the prevalence of PAD, CAS, and AAA with advanced age. More than 20% and 30% of octogenarians and nonagenarians, respectively, have vascular disease in at least 1 arterial territory.

A model for predicting the risk of carotid artery disease.

OBJECTIVE: To develop a model for the identification of individuals at risk for carotid stenosis (CS) that could be useful in a clinical setting when trying to decide whether screening is worthwhile. BACKGROUND: Evidence that aggressive medical therapy and life style changes reduce the risk of stroke in individuals with CS is increasing and has led to a renewed interest in screening for CS. METHODS: Data on demographics and risk factors were obtained from 2,885,257 individuals who had carotid Duplex scans by Life Line Screening between 2003 and 2008. Multivariable logistic regression analysis was used to identify independent risk factors for CS (>50% stenosis). A scoring system was developed where risk factors were assigned a weighted score. Predictive ability was assessed by calculating C statistics and r2. RESULTS: In the screened cohort, 71,004 patients (2.4%) had CS. Independent risk factors include advanced age, smoking, peripheral arterial disease, high blood pressure, coronary artery disease, diabetes, cholesterol, and abdominal aortic aneurysm. African Americans, Asians, and Hispanics had reduced risk than whites. Exercise and consumption of fruit, vegetables, and nuts had a modest protective effect. A predictive scoring system was created that identifies individuals with CS more efficiently (C statistic = 0.753) than previously published models. CONCLUSIONS: We provide a model that enables identification of individuals who have a high probability of having CS. This model can be helpful in designing targeted screening programs that are cost-effective.

The prevalence of carotid artery stenosis varies significantly by race.

OBJECTIVE: Certain races are known to be at increased risk for stroke, and the prevalence of carotid artery stenosis (CAS) is thought to vary by race. The goal of this report was to study the prevalence of CAS in different races by analyzing a population of subjects who underwent vascular screening examinations. METHODS: The study data were provided by Life Line Screening. The cohort consists of self-referred individuals who paid for vascular screening tests. Subjects <40 and >100 years of age and those who reported a prior stroke or carotid artery intervention were excluded. Of the remaining 3,291,382 subjects, 3.7% did not self-identify a race. CAS was defined as stenosis in either internal carotid artery ≥50% by duplex ultrasound velocity criteria. RESULTS: The 3,291,382 subjects available for analysis consisted of Caucasian (2,845,936 [90%]), African American (97,502 [3.1%]), Hispanic (75,240 [2.4%]), Asian (60,982 [1.9%]), and Native American (87,757 [2.8%]) individuals. The prevalence of CAS was 3.4% in females and 4.2% in males (P ≤ .001). Controlling for gender and age, there was marked variation in the prevalence of CAS (P < .001) by race. Native American subjects had the highest prevalence of CAS across all age categories and in both sexes. Caucasian subjects had the second highest prevalence of CAS across most age decades and in both sexes. Among males, African American individuals had the lowest prevalence of CAS in nearly all age categories. In contrast to males, Asian females had the lowest prevalence of CAS compared with females of other races in most age groups. Multivariate analysis adjusting for atherosclerotic risk factors in addition to age confirmed race as a significant independent predictor of CAS. Compared with Caucasian subjects, African American (odds ratio [OR], 0.65), Asian (OR, 0.69), and Hispanic (OR, 0.74) subjects had a significantly lower risk of CAS, whereas Native American (OR, 1.3) subjects had a significantly higher risk of CAS. CONCLUSIONS: The prevalence of clinically significant CAS varies significantly by race. Native American and Caucasian individuals have the highest prevalence of CAS, whereas African American males and Asian females appear to have the lowest prevalence. This information adds evidence to the hypothesis that the increased stroke rate in African American subjects is likely not related to extracranial cerebrovascular disease. Furthermore, this is a novel report of an extremely high prevalence of CAS in the Native American population.