@article {1195, title = {Prevalence of asymptomatic carotid artery stenosis in the general population: an individual participant data meta-analysis.}, journal = {Stroke}, volume = {41}, year = {2010}, month = {2010 Jun}, pages = {1294-7}, abstract = {

BACKGROUND AND PURPOSE: In the discussion on the cost-effectiveness of screening, precise estimates of severe asymptomatic carotid stenosis are vital. Accordingly, we assessed the prevalence of moderate and severe asymptomatic carotid stenosis by age and sex using pooled cohort data.

METHODS: We performed an individual participant data meta-analysis (23 706 participants) of 4 population-based studies (Malm{\"o} Diet and Cancer Study, Troms{\o}, Carotid Atherosclerosis Progression Study, and Cardiovascular Health Study). Outcomes of interest were asymptomatic moderate (> or =50\%) and severe carotid stenosis (> or =70\%).

RESULTS: Prevalence of moderate asymptomatic carotid stenosis ranged from 0.2\% (95\% CI, 0.0\% to 0.4\%) in men aged <50 years to 7.5\% (5.2\% to 10.5\%) in men aged > or =80 years. For women, this prevalence increased from 0\% (0\% to 0.2\%) to 5.0\% (3.1\% to 7.5\%). Prevalence of severe asymptomatic carotid stenosis ranged from 0.1\% (0.0\% to 0.3\%) in men aged <50 years to 3.1\% (1.7\% to 5.3\%) in men aged > or =80. For women, this prevalence increased from 0\% (0.0\% to 0.2\%) to 0.9\% (0.3\% to 2.4\%).

CONCLUSIONS: The prevalence of severe asymptomatic carotid stenosis in the general population ranges from 0\% to 3.1\%, which is useful information in the discussion on the cost-effectiveness of screening.

}, keywords = {Adult, Age Factors, Aged, Aged, 80 and over, Carotid Stenosis, Female, Humans, Male, Mass Screening, Middle Aged, Prevalence, Severity of Illness Index, Sex Factors}, issn = {1524-4628}, doi = {10.1161/STROKEAHA.110.581058}, author = {de Weerd, Marjolein and Greving, Jacoba P and Hedblad, Bo and Lorenz, Matthias W and Mathiesen, Ellisiv B and O{\textquoteright}Leary, Daniel H and Rosvall, Maria and Sitzer, Matthias and Buskens, Erik and Bots, Michiel L} } @article {6557, title = {Prediction of asymptomatic carotid artery stenosis in the general population: identification of high-risk groups.}, journal = {Stroke}, volume = {45}, year = {2014}, month = {2014 Aug}, pages = {2366-71}, abstract = {

BACKGROUND AND PURPOSE: Because of a low prevalence of severe carotid stenosis in the general population, screening for presence of asymptomatic carotid artery stenosis (ACAS) is not warranted. Possibly, for certain subgroups, screening is worthwhile. The present study aims to develop prediction rules for the presence of ACAS (>50\% and >70\%).

METHODS: Individual participant data from 4 population-based cohort studies (Malm{\"o} Diet and Cancer Study, Troms{\o} Study, Carotid Atherosclerosis Progression Study, and Cardiovascular Health Study; totaling 23 706 participants) were pooled. Multivariable logistic regression was performed to determine which variables predict presence of ACAS (>50\% and >70\%). Calibration and discrimination of the models were assessed, and bootstrapping was used to correct for overfitting.

RESULTS: Age, sex, history of vascular disease, systolic and diastolic blood pressure, total cholesterol/high-density lipoprotein ratio, diabetes mellitus, and current smoking were predictors of stenosis (>50\% and >70\%). The calibration of the model was good confirmed by a nonsignificant Hosmer and Lemeshow test for moderate (P=0.59) and severe stenosis (P=0.07). The models discriminated well between participants with and without stenosis, with an area under the receiver operating characteristic curve corrected for over optimism of 0.82 (95\% confidence interval, 0.80-0.84) for moderate stenosis and of 0.87 (95\% confidence interval, 0.85-0.90) for severe stenosis. The regression coefficients of the predictors were converted into a score chart to facilitate practical application.

CONCLUSIONS: A clinical prediction rule was developed that allows identification of subgroups with high prevalence of moderate (>50\%) and severe (>70\%) ACAS. When confirmed in comparable cohorts, application of the prediction rule may lead to a reduction in the number needed to screen for ACAS.

}, keywords = {Adult, Age Factors, Aged, Aged, 80 and over, Blood Pressure, Carotid Stenosis, Female, Humans, Life Style, Male, Mass Screening, Middle Aged, Prevalence, Registries, Risk, Smoking}, issn = {1524-4628}, doi = {10.1161/STROKEAHA.114.005145}, author = {de Weerd, Marjolein and Greving, Jacoba P and Hedblad, Bo and Lorenz, Matthias W and Mathiesen, Ellisiv B and O{\textquoteright}Leary, Daniel H and Rosvall, Maria and Sitzer, Matthias and de Borst, Gert Jan and Buskens, Erik and Bots, Michiel L} }