Bart Ferket | Mt Sinai School Of Medicine (original) (raw)
Papers by Bart Ferket
PLoS ONE, 2014
Background: According to population-based cohort studies CT coronary calcium score (CTCS), caroti... more Background: According to population-based cohort studies CT coronary calcium score (CTCS), carotid intima-media thickness (cIMT), high-sensitivity C-reactive protein (CRP), and ankle-brachial index (ABI) are promising novel risk markers for improving cardiovascular risk assessment. Their impact in the U.S. general population is however uncertain. Our aim was to estimate the predictive value of four novel cardiovascular risk markers for the U.S. general population.
BMC Medicine, 2012
We developed a Monte Carlo Markov model designed to investigate the effects of modifying cardiova... more We developed a Monte Carlo Markov model designed to investigate the effects of modifying cardiovascular disease (CVD) risk factors on the burden of CVD. Internal, predictive, and external validity of the model have not yet been established. The Rotterdam Ischemic Heart Disease and Stroke Computer Simulation (RISC) model was developed using data covering 5 years of follow-up from the Rotterdam Study. To prove 1) internal and 2) predictive validity, the incidences of coronary heart disease (CHD), stroke, CVD death, and non-CVD death simulated by the model over a 13-year period were compared with those recorded for 3,478 participants in the Rotterdam Study with at least 13 years of follow-up. 3) External validity was verified using 10 years of follow-up data from the European Prospective Investigation of Cancer (EPIC)-Norfolk study of 25,492 participants, for whom CVD and non-CVD mortality was compared. At year 5, the observed incidences (with simulated incidences in brackets) of CHD, stroke, and CVD and non-CVD mortality for the 3,478 Rotterdam Study participants were 5.30% (4.68%), 3.60% (3.23%), 4.70% (4.80%), and 7.50% (7.96%), respectively. At year 13, these percentages were 10.60% (10.91%), 9.90% (9.13%), 14.20% (15.12%), and 24.30% (23.42%). After recalibrating the model for the EPIC-Norfolk population, the 10-year observed (simulated) incidences of CVD and non-CVD mortality were 3.70% (4.95%) and 6.50% (6.29%). All observed incidences fell well within the 95% credibility intervals of the simulated incidences. We have confirmed the internal, predictive, and external validity of the RISC model. These findings provide a basis for analyzing the effects of modifying cardiovascular disease risk factors on the burden of CVD with the RISC model.
Medical decision making : an international journal of the Society for Medical Decision Making
Modeling studies that evaluate statin treatment for the prevention of cardiovascular disease (CVD... more Modeling studies that evaluate statin treatment for the prevention of cardiovascular disease (CVD) use different methods to model the effect of statins. The aim of this study was to evaluate the impact of using different modeling methods on the optimal decision found in such studies. We used a previously developed and validated Monte Carlo-Markov model based on the Rotterdam study (RISC model). The RISC model simulates coronary heart disease (CHD), stroke, cardiovascular death, and death due to other causes. Transition probabilities were based on 5-year risks predicted by Cox regression equations, including (among others) total and high-density lipoprotein (HDL) cholesterol as covariates. In a cost-effectiveness analysis of implementing the ATP-III guidelines, we evaluated the impact of using 3 different modeling methods of statin effectiveness: 1) through lipid level modification: statins lower total cholesterol and increase HDL cholesterol, which through the covariates in the Cox ...
International Journal of Cardiology, 2014
Background: To evaluate the performance of Framingham predictions of cardiovascular disease (CVD)... more Background: To evaluate the performance of Framingham predictions of cardiovascular disease (CVD) risk corrected for the competing risk of non-CVD death, in an independent European cohort of older individuals and subsequently extend the predictions by disentangling CVD into coronary heart disease (CHD) and stroke separately. Methods: We used the Rotterdam Study data, a prospective cohort study of individuals aged 55 years and older (N = 6004), to validate the Framingham predictions of CVD, defined as first occurrence of myocardial infarction, coronary death or stroke during 15 years of follow-up, corrected for the competing risk of non-CVD death. We subsequently estimated the risks of CHD and stroke separately, and used the sum as a predictor for the total CVD risk. Calibration plots and c-statistics were used to evaluate the performance of the models. Results: Performance of the Framingham predictions was good in the low-to intermediate risk (≤30%, 15-year CVD risk) (17.5% observed vs. 16.6% expected) but poorer in the higher risk (N30%) categories (36.3% observed vs. 44.1% expected). The c-statistic increased from 0.66 to 0.69 after refitting. Separately estimating CHD and stroke revealed considerable heterogeneity with regard to the contribution of CHD and stroke to total CVD risk. Conclusions: Framingham CVD risk predictions perform well in the low-to intermediate risk categories in the Rotterdam Study. Disentangling CVD into CHD and stroke separately provides additional information about the individual contribution of CHD and stroke to total individual CVD risk.
Neurology, 2014
To develop and validate 10-year cumulative incidence functions of intracerebral hemorrhage (ICH) ... more To develop and validate 10-year cumulative incidence functions of intracerebral hemorrhage (ICH) and ischemic stroke (IS). We used data on 27,493 participants from 3 population-based cohort studies: the Atherosclerosis Risk in Communities Study, median age 54 years, 45% male, median follow-up 20.7 years; the Rotterdam Study, median age 68 years, 38% male, median follow-up 14.3 years; and the Cardiovascular Health Study, median age 71 years, 41% male, median follow-up 12.8 years. Among these participants, 325 ICH events, 2,559 IS events, and 9,909 nonstroke deaths occurred. We developed 10-year cumulative incidence functions for ICH and IS using stratified Cox regression and competing risks analysis. Basic models including only established nonlaboratory risk factors were extended with diastolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, body mass index, waist-to-hip ratio, and glomerular filtration rate. The cumulative incidence functions' performances were cross-validated in each cohort separately by Harrell C-statistic and calibration plots. High total cholesterol/high-density lipoprotein cholesterol ratio decreased the ICH rates but increased IS rates (p for difference across stroke types <0.001). For both the ICH and IS models, C statistics increased more by model extension in the Atherosclerosis Risk in Communities and Cardiovascular Health Study cohorts. Improvements in C statistics were reproduced by cross-validation. Models were well calibrated in all cohorts. Correlations between 10-year ICH and IS risks were moderate in each cohort. We developed and cross-validated cumulative incidence functions for separate prediction of 10-year ICH and IS risk. These functions can be useful to further specify an individual's stroke risk.
Vascular Health and Risk Management, 2011
Introduction: A large proportion of the cardiovascular disease (CVD) burden can potentially be pr... more Introduction: A large proportion of the cardiovascular disease (CVD) burden can potentially be prevented by primary prevention programs addressing major causal risk factors. A Web- based health risk assessment (HRA) with tailored feedback for individual health promotion is a promising strategy. We evaluated the effect on CVD risk of such a program among employees of a Dutch worksite. Methods: We
Archives of internal medicine, Jan 11, 2010
To appraise guidelines on cardiovascular risk assessment to guide selection of screening interven... more To appraise guidelines on cardiovascular risk assessment to guide selection of screening interventions for a health check. Guidelines in the English language published between January 1, 2003, and May 2, 2009, were retrieved using MEDLINE and CINAHL. This was supplemented by searching the National Guideline Clearinghouse, National Library for Health, Canadian Medical Association Infobase, and G-I-N International Guideline Library. We included guidelines developed on behalf of professional organizations from Western countries, containing recommendations on cardiovascular risk assessment for the apparently healthy population. Titles and abstracts were assessed by 2 independent reviewers. Of 1984 titles identified, 27 guidelines met our criteria. Rigor of guideline development was assessed by 2 independent reviewers. One reviewer extracted information on conflicts of interest and recommendations. Sixteen of 27 guidelines reported conflicts of interest and 17 showed considerable rigor. ...
PLoS medicine, 2012
Physicians need to inform asymptomatic individuals about personalized outcomes of statin therapy ... more Physicians need to inform asymptomatic individuals about personalized outcomes of statin therapy for primary prevention of cardiovascular disease (CVD). However, current prediction models focus on short-term outcomes and ignore the competing risk of death due to other causes. We aimed to predict the potential lifetime benefits with statin therapy, taking into account competing risks. A microsimulation model based on 5-y follow-up data from the Rotterdam Study, a population-based cohort of individuals aged 55 y and older living in the Ommoord district of Rotterdam, the Netherlands, was used to estimate lifetime outcomes with and without statin therapy. The model was validated in-sample using 10-y follow-up data. We used baseline variables and model output to construct (1) a web-based calculator for gains in total and CVD-free life expectancy and (2) color charts for comparing these gains to the Systematic Coronary Risk Evaluation (SCORE) charts. In 2,428 participants (mean age 67.7 y...
PLoS ONE, 2014
Background: According to population-based cohort studies CT coronary calcium score (CTCS), caroti... more Background: According to population-based cohort studies CT coronary calcium score (CTCS), carotid intima-media thickness (cIMT), high-sensitivity C-reactive protein (CRP), and ankle-brachial index (ABI) are promising novel risk markers for improving cardiovascular risk assessment. Their impact in the U.S. general population is however uncertain. Our aim was to estimate the predictive value of four novel cardiovascular risk markers for the U.S. general population.
Neurology, 2014
To develop and validate 10-year cumulative incidence functions of intracerebral hemorrhage (ICH) ... more To develop and validate 10-year cumulative incidence functions of intracerebral hemorrhage (ICH) and ischemic stroke (IS). We used data on 27,493 participants from 3 population-based cohort studies: the Atherosclerosis Risk in Communities Study, median age 54 years, 45% male, median follow-up 20.7 years; the Rotterdam Study, median age 68 years, 38% male, median follow-up 14.3 years; and the Cardiovascular Health Study, median age 71 years, 41% male, median follow-up 12.8 years. Among these participants, 325 ICH events, 2,559 IS events, and 9,909 nonstroke deaths occurred. We developed 10-year cumulative incidence functions for ICH and IS using stratified Cox regression and competing risks analysis. Basic models including only established nonlaboratory risk factors were extended with diastolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, body mass index, waist-to-hip ratio, and glomerular filtration rate. The cumulative incidence functions' performances were cross-validated in each cohort separately by Harrell C-statistic and calibration plots. High total cholesterol/high-density lipoprotein cholesterol ratio decreased the ICH rates but increased IS rates (p for difference across stroke types <0.001). For both the ICH and IS models, C statistics increased more by model extension in the Atherosclerosis Risk in Communities and Cardiovascular Health Study cohorts. Improvements in C statistics were reproduced by cross-validation. Models were well calibrated in all cohorts. Correlations between 10-year ICH and IS risks were moderate in each cohort. We developed and cross-validated cumulative incidence functions for separate prediction of 10-year ICH and IS risk. These functions can be useful to further specify an individual's stroke risk.
Journal of Vascular Surgery, 2012
Results: Of 2415 titles identified, seven guidelines were included in this review. Three guidelin... more Results: Of 2415 titles identified, seven guidelines were included in this review. Three guidelines were less rigorously developed based on AGREE scores below 40%. All seven guidelines contained a recommendation for one-time screening of elderly men by ultrasonography to select AAAs >5.5 cm for elective surgical repair. Four guidelines, of which three were less rigorously developed, contained disparate recommendations on screening of women and middle-aged men at elevated risk. There was no agreement on the management of smaller AAAs.
The purpose of this study was to critically appraise guidelines on imaging of asymptomatic corona... more The purpose of this study was to critically appraise guidelines on imaging of asymptomatic coronary artery disease (CAD).
International Journal of Cardiology, 2014
Background: To evaluate the performance of Framingham predictions of cardiovascular disease (CVD)... more Background: To evaluate the performance of Framingham predictions of cardiovascular disease (CVD) risk corrected for the competing risk of non-CVD death, in an independent European cohort of older individuals and subsequently extend the predictions by disentangling CVD into coronary heart disease (CHD) and stroke separately. Methods: We used the Rotterdam Study data, a prospective cohort study of individuals aged 55 years and older (N = 6004), to validate the Framingham predictions of CVD, defined as first occurrence of myocardial infarction, coronary death or stroke during 15 years of follow-up, corrected for the competing risk of non-CVD death. We subsequently estimated the risks of CHD and stroke separately, and used the sum as a predictor for the total CVD risk. Calibration plots and c-statistics were used to evaluate the performance of the models. Results: Performance of the Framingham predictions was good in the low-to intermediate risk (≤30%, 15-year CVD risk) (17.5% observed vs. 16.6% expected) but poorer in the higher risk (N30%) categories (36.3% observed vs. 44.1% expected). The c-statistic increased from 0.66 to 0.69 after refitting. Separately estimating CHD and stroke revealed considerable heterogeneity with regard to the contribution of CHD and stroke to total CVD risk. Conclusions: Framingham CVD risk predictions perform well in the low-to intermediate risk categories in the Rotterdam Study. Disentangling CVD into CHD and stroke separately provides additional information about the individual contribution of CHD and stroke to total individual CVD risk.
Archives of Internal Medicine, 2010
To appraise guidelines on cardiovascular risk assessment to guide selection of screening interven... more To appraise guidelines on cardiovascular risk assessment to guide selection of screening interventions for a health check. Guidelines in the English language published between January 1, 2003, and May 2, 2009, were retrieved using MEDLINE and CINAHL. This was supplemented by searching the National Guideline Clearinghouse, National Library for Health, Canadian Medical Association Infobase, and G-I-N International Guideline Library. We included guidelines developed on behalf of professional organizations from Western countries, containing recommendations on cardiovascular risk assessment for the apparently healthy population. Titles and abstracts were assessed by 2 independent reviewers. Of 1984 titles identified, 27 guidelines met our criteria. Rigor of guideline development was assessed by 2 independent reviewers. One reviewer extracted information on conflicts of interest and recommendations. Sixteen of 27 guidelines reported conflicts of interest and 17 showed considerable rigor. These included recommendations on assessment of total cardiovascular risk (7 guidelines), dyslipidemia (2), hypertension (2), and dysglycemia (7). Recommendations on total cardiovascular risk and dyslipidemia included prediction models integrating multiple risk factors, whereas remaining recommendations were focused on single risk factors. No consensus was found on recommended target populations, treatment thresholds, and screening tests. Differences among the guidelines imply important variation in allocation of preventive interventions. To make informed decisions, physicians should use only the recommendations from rigorously developed guidelines.
The American Journal of Medicine, 2012
BACKGROUND: Peripheral artery disease (PAD) screening may be performed to prevent progression of ... more BACKGROUND: Peripheral artery disease (PAD) screening may be performed to prevent progression of PAD or future cardiovascular disease in general. Recommendations for PAD screening have to be derived indirectly because no randomized trials comparing screening versus no screening have been performed. We performed a systematic review of guidelines to evaluate the value of PAD screening in asymptomatic adults. national and international medical societies from Western countries, containing recommendations on PAD screening, were included. Two reviewers independently assessed rigor of guideline development using the Appraisal of Guidelines Research and Evaluation (AGREE) instrument. One reviewer performed full extraction of recommendations, which was validated by a second reviewer. RESULTS: Of 2779 titles identified, 8 guidelines were included. AGREE scores varied from 33% to 81%. Five guidelines advocated PAD screening, others found insufficient evidence for PAD screening or were against it. Measurement of the ankle-brachial index (ABI) was generally recommended for middle-aged populations with elevated cardiovascular risk levels. Those identified as having PAD are reclassified as high risk, warranting intensive preventive interventions to reduce their risk of a cardiovascular event. The underlying evidence mainly consisted of studies performed in patients with established PAD. A meta-analysis that evaluated ABI testing in the context of traditional cardiovascular risk assessment was interpreted differently. CONCLUSIONS: Recommendations on PAD screening vary across current guidelines, making the value of PAD screening uncertain. The variation seems to reflect lack of studies that show added value of detection of early PAD beyond expectant management and traditional risk assessment.
JAMA - Journal of the American Medical Association, 2010
... Nancy R. Cook, ScD ncook{at}rics.bwh.harvard.eduBrigham and Women's HospitalBoston, ... more ... Nancy R. Cook, ScD ncook{at}rics.bwh.harvard.eduBrigham and Women's HospitalBoston, Massachusetts; Karel GM Moons, MD, PhDUMC UtrechtUtrecht, the Netherlands; Frank E. Harrell, Jr ... doi:10.1373/clinchem.2009.134155, pmid:20133890. Free Full Text. 4. Harrell FE Jr. . ...
BMJ (Clinical research ed.), 2014
To evaluate differences in first manifestations of cardiovascular disease between men and women i... more To evaluate differences in first manifestations of cardiovascular disease between men and women in a competing risks framework. Prospective population based cohort study. People living in the community in Rotterdam, the Netherlands. 8419 participants (60.9% women) aged ≥ 55 and free from cardiovascular disease at baseline. First diagnosis of coronary heart disease (myocardial infarction, revascularisation, and coronary death), cerebrovascular disease (stroke, transient ischaemic attack, and carotid revascularisation), heart failure, or other cardiovascular death; or death from non-cardiovascular causes. Data were used to calculate lifetime risks of cardiovascular disease and its first incident manifestations adjusted for competing non-cardiovascular death. During follow-up of up to 20.1 years, 2888 participants developed cardiovascular disease (826 coronary heart disease, 1198 cerebrovascular disease, 762 heart failure, and 102 other cardiovascular death). At age 55, overall lifetim...
PLoS ONE, 2014
Background: According to population-based cohort studies CT coronary calcium score (CTCS), caroti... more Background: According to population-based cohort studies CT coronary calcium score (CTCS), carotid intima-media thickness (cIMT), high-sensitivity C-reactive protein (CRP), and ankle-brachial index (ABI) are promising novel risk markers for improving cardiovascular risk assessment. Their impact in the U.S. general population is however uncertain. Our aim was to estimate the predictive value of four novel cardiovascular risk markers for the U.S. general population.
BMC Medicine, 2012
We developed a Monte Carlo Markov model designed to investigate the effects of modifying cardiova... more We developed a Monte Carlo Markov model designed to investigate the effects of modifying cardiovascular disease (CVD) risk factors on the burden of CVD. Internal, predictive, and external validity of the model have not yet been established. The Rotterdam Ischemic Heart Disease and Stroke Computer Simulation (RISC) model was developed using data covering 5 years of follow-up from the Rotterdam Study. To prove 1) internal and 2) predictive validity, the incidences of coronary heart disease (CHD), stroke, CVD death, and non-CVD death simulated by the model over a 13-year period were compared with those recorded for 3,478 participants in the Rotterdam Study with at least 13 years of follow-up. 3) External validity was verified using 10 years of follow-up data from the European Prospective Investigation of Cancer (EPIC)-Norfolk study of 25,492 participants, for whom CVD and non-CVD mortality was compared. At year 5, the observed incidences (with simulated incidences in brackets) of CHD, stroke, and CVD and non-CVD mortality for the 3,478 Rotterdam Study participants were 5.30% (4.68%), 3.60% (3.23%), 4.70% (4.80%), and 7.50% (7.96%), respectively. At year 13, these percentages were 10.60% (10.91%), 9.90% (9.13%), 14.20% (15.12%), and 24.30% (23.42%). After recalibrating the model for the EPIC-Norfolk population, the 10-year observed (simulated) incidences of CVD and non-CVD mortality were 3.70% (4.95%) and 6.50% (6.29%). All observed incidences fell well within the 95% credibility intervals of the simulated incidences. We have confirmed the internal, predictive, and external validity of the RISC model. These findings provide a basis for analyzing the effects of modifying cardiovascular disease risk factors on the burden of CVD with the RISC model.
Medical decision making : an international journal of the Society for Medical Decision Making
Modeling studies that evaluate statin treatment for the prevention of cardiovascular disease (CVD... more Modeling studies that evaluate statin treatment for the prevention of cardiovascular disease (CVD) use different methods to model the effect of statins. The aim of this study was to evaluate the impact of using different modeling methods on the optimal decision found in such studies. We used a previously developed and validated Monte Carlo-Markov model based on the Rotterdam study (RISC model). The RISC model simulates coronary heart disease (CHD), stroke, cardiovascular death, and death due to other causes. Transition probabilities were based on 5-year risks predicted by Cox regression equations, including (among others) total and high-density lipoprotein (HDL) cholesterol as covariates. In a cost-effectiveness analysis of implementing the ATP-III guidelines, we evaluated the impact of using 3 different modeling methods of statin effectiveness: 1) through lipid level modification: statins lower total cholesterol and increase HDL cholesterol, which through the covariates in the Cox ...
International Journal of Cardiology, 2014
Background: To evaluate the performance of Framingham predictions of cardiovascular disease (CVD)... more Background: To evaluate the performance of Framingham predictions of cardiovascular disease (CVD) risk corrected for the competing risk of non-CVD death, in an independent European cohort of older individuals and subsequently extend the predictions by disentangling CVD into coronary heart disease (CHD) and stroke separately. Methods: We used the Rotterdam Study data, a prospective cohort study of individuals aged 55 years and older (N = 6004), to validate the Framingham predictions of CVD, defined as first occurrence of myocardial infarction, coronary death or stroke during 15 years of follow-up, corrected for the competing risk of non-CVD death. We subsequently estimated the risks of CHD and stroke separately, and used the sum as a predictor for the total CVD risk. Calibration plots and c-statistics were used to evaluate the performance of the models. Results: Performance of the Framingham predictions was good in the low-to intermediate risk (≤30%, 15-year CVD risk) (17.5% observed vs. 16.6% expected) but poorer in the higher risk (N30%) categories (36.3% observed vs. 44.1% expected). The c-statistic increased from 0.66 to 0.69 after refitting. Separately estimating CHD and stroke revealed considerable heterogeneity with regard to the contribution of CHD and stroke to total CVD risk. Conclusions: Framingham CVD risk predictions perform well in the low-to intermediate risk categories in the Rotterdam Study. Disentangling CVD into CHD and stroke separately provides additional information about the individual contribution of CHD and stroke to total individual CVD risk.
Neurology, 2014
To develop and validate 10-year cumulative incidence functions of intracerebral hemorrhage (ICH) ... more To develop and validate 10-year cumulative incidence functions of intracerebral hemorrhage (ICH) and ischemic stroke (IS). We used data on 27,493 participants from 3 population-based cohort studies: the Atherosclerosis Risk in Communities Study, median age 54 years, 45% male, median follow-up 20.7 years; the Rotterdam Study, median age 68 years, 38% male, median follow-up 14.3 years; and the Cardiovascular Health Study, median age 71 years, 41% male, median follow-up 12.8 years. Among these participants, 325 ICH events, 2,559 IS events, and 9,909 nonstroke deaths occurred. We developed 10-year cumulative incidence functions for ICH and IS using stratified Cox regression and competing risks analysis. Basic models including only established nonlaboratory risk factors were extended with diastolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, body mass index, waist-to-hip ratio, and glomerular filtration rate. The cumulative incidence functions' performances were cross-validated in each cohort separately by Harrell C-statistic and calibration plots. High total cholesterol/high-density lipoprotein cholesterol ratio decreased the ICH rates but increased IS rates (p for difference across stroke types <0.001). For both the ICH and IS models, C statistics increased more by model extension in the Atherosclerosis Risk in Communities and Cardiovascular Health Study cohorts. Improvements in C statistics were reproduced by cross-validation. Models were well calibrated in all cohorts. Correlations between 10-year ICH and IS risks were moderate in each cohort. We developed and cross-validated cumulative incidence functions for separate prediction of 10-year ICH and IS risk. These functions can be useful to further specify an individual's stroke risk.
Vascular Health and Risk Management, 2011
Introduction: A large proportion of the cardiovascular disease (CVD) burden can potentially be pr... more Introduction: A large proportion of the cardiovascular disease (CVD) burden can potentially be prevented by primary prevention programs addressing major causal risk factors. A Web- based health risk assessment (HRA) with tailored feedback for individual health promotion is a promising strategy. We evaluated the effect on CVD risk of such a program among employees of a Dutch worksite. Methods: We
Archives of internal medicine, Jan 11, 2010
To appraise guidelines on cardiovascular risk assessment to guide selection of screening interven... more To appraise guidelines on cardiovascular risk assessment to guide selection of screening interventions for a health check. Guidelines in the English language published between January 1, 2003, and May 2, 2009, were retrieved using MEDLINE and CINAHL. This was supplemented by searching the National Guideline Clearinghouse, National Library for Health, Canadian Medical Association Infobase, and G-I-N International Guideline Library. We included guidelines developed on behalf of professional organizations from Western countries, containing recommendations on cardiovascular risk assessment for the apparently healthy population. Titles and abstracts were assessed by 2 independent reviewers. Of 1984 titles identified, 27 guidelines met our criteria. Rigor of guideline development was assessed by 2 independent reviewers. One reviewer extracted information on conflicts of interest and recommendations. Sixteen of 27 guidelines reported conflicts of interest and 17 showed considerable rigor. ...
PLoS medicine, 2012
Physicians need to inform asymptomatic individuals about personalized outcomes of statin therapy ... more Physicians need to inform asymptomatic individuals about personalized outcomes of statin therapy for primary prevention of cardiovascular disease (CVD). However, current prediction models focus on short-term outcomes and ignore the competing risk of death due to other causes. We aimed to predict the potential lifetime benefits with statin therapy, taking into account competing risks. A microsimulation model based on 5-y follow-up data from the Rotterdam Study, a population-based cohort of individuals aged 55 y and older living in the Ommoord district of Rotterdam, the Netherlands, was used to estimate lifetime outcomes with and without statin therapy. The model was validated in-sample using 10-y follow-up data. We used baseline variables and model output to construct (1) a web-based calculator for gains in total and CVD-free life expectancy and (2) color charts for comparing these gains to the Systematic Coronary Risk Evaluation (SCORE) charts. In 2,428 participants (mean age 67.7 y...
PLoS ONE, 2014
Background: According to population-based cohort studies CT coronary calcium score (CTCS), caroti... more Background: According to population-based cohort studies CT coronary calcium score (CTCS), carotid intima-media thickness (cIMT), high-sensitivity C-reactive protein (CRP), and ankle-brachial index (ABI) are promising novel risk markers for improving cardiovascular risk assessment. Their impact in the U.S. general population is however uncertain. Our aim was to estimate the predictive value of four novel cardiovascular risk markers for the U.S. general population.
Neurology, 2014
To develop and validate 10-year cumulative incidence functions of intracerebral hemorrhage (ICH) ... more To develop and validate 10-year cumulative incidence functions of intracerebral hemorrhage (ICH) and ischemic stroke (IS). We used data on 27,493 participants from 3 population-based cohort studies: the Atherosclerosis Risk in Communities Study, median age 54 years, 45% male, median follow-up 20.7 years; the Rotterdam Study, median age 68 years, 38% male, median follow-up 14.3 years; and the Cardiovascular Health Study, median age 71 years, 41% male, median follow-up 12.8 years. Among these participants, 325 ICH events, 2,559 IS events, and 9,909 nonstroke deaths occurred. We developed 10-year cumulative incidence functions for ICH and IS using stratified Cox regression and competing risks analysis. Basic models including only established nonlaboratory risk factors were extended with diastolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, body mass index, waist-to-hip ratio, and glomerular filtration rate. The cumulative incidence functions' performances were cross-validated in each cohort separately by Harrell C-statistic and calibration plots. High total cholesterol/high-density lipoprotein cholesterol ratio decreased the ICH rates but increased IS rates (p for difference across stroke types <0.001). For both the ICH and IS models, C statistics increased more by model extension in the Atherosclerosis Risk in Communities and Cardiovascular Health Study cohorts. Improvements in C statistics were reproduced by cross-validation. Models were well calibrated in all cohorts. Correlations between 10-year ICH and IS risks were moderate in each cohort. We developed and cross-validated cumulative incidence functions for separate prediction of 10-year ICH and IS risk. These functions can be useful to further specify an individual's stroke risk.
Journal of Vascular Surgery, 2012
Results: Of 2415 titles identified, seven guidelines were included in this review. Three guidelin... more Results: Of 2415 titles identified, seven guidelines were included in this review. Three guidelines were less rigorously developed based on AGREE scores below 40%. All seven guidelines contained a recommendation for one-time screening of elderly men by ultrasonography to select AAAs >5.5 cm for elective surgical repair. Four guidelines, of which three were less rigorously developed, contained disparate recommendations on screening of women and middle-aged men at elevated risk. There was no agreement on the management of smaller AAAs.
The purpose of this study was to critically appraise guidelines on imaging of asymptomatic corona... more The purpose of this study was to critically appraise guidelines on imaging of asymptomatic coronary artery disease (CAD).
International Journal of Cardiology, 2014
Background: To evaluate the performance of Framingham predictions of cardiovascular disease (CVD)... more Background: To evaluate the performance of Framingham predictions of cardiovascular disease (CVD) risk corrected for the competing risk of non-CVD death, in an independent European cohort of older individuals and subsequently extend the predictions by disentangling CVD into coronary heart disease (CHD) and stroke separately. Methods: We used the Rotterdam Study data, a prospective cohort study of individuals aged 55 years and older (N = 6004), to validate the Framingham predictions of CVD, defined as first occurrence of myocardial infarction, coronary death or stroke during 15 years of follow-up, corrected for the competing risk of non-CVD death. We subsequently estimated the risks of CHD and stroke separately, and used the sum as a predictor for the total CVD risk. Calibration plots and c-statistics were used to evaluate the performance of the models. Results: Performance of the Framingham predictions was good in the low-to intermediate risk (≤30%, 15-year CVD risk) (17.5% observed vs. 16.6% expected) but poorer in the higher risk (N30%) categories (36.3% observed vs. 44.1% expected). The c-statistic increased from 0.66 to 0.69 after refitting. Separately estimating CHD and stroke revealed considerable heterogeneity with regard to the contribution of CHD and stroke to total CVD risk. Conclusions: Framingham CVD risk predictions perform well in the low-to intermediate risk categories in the Rotterdam Study. Disentangling CVD into CHD and stroke separately provides additional information about the individual contribution of CHD and stroke to total individual CVD risk.
Archives of Internal Medicine, 2010
To appraise guidelines on cardiovascular risk assessment to guide selection of screening interven... more To appraise guidelines on cardiovascular risk assessment to guide selection of screening interventions for a health check. Guidelines in the English language published between January 1, 2003, and May 2, 2009, were retrieved using MEDLINE and CINAHL. This was supplemented by searching the National Guideline Clearinghouse, National Library for Health, Canadian Medical Association Infobase, and G-I-N International Guideline Library. We included guidelines developed on behalf of professional organizations from Western countries, containing recommendations on cardiovascular risk assessment for the apparently healthy population. Titles and abstracts were assessed by 2 independent reviewers. Of 1984 titles identified, 27 guidelines met our criteria. Rigor of guideline development was assessed by 2 independent reviewers. One reviewer extracted information on conflicts of interest and recommendations. Sixteen of 27 guidelines reported conflicts of interest and 17 showed considerable rigor. These included recommendations on assessment of total cardiovascular risk (7 guidelines), dyslipidemia (2), hypertension (2), and dysglycemia (7). Recommendations on total cardiovascular risk and dyslipidemia included prediction models integrating multiple risk factors, whereas remaining recommendations were focused on single risk factors. No consensus was found on recommended target populations, treatment thresholds, and screening tests. Differences among the guidelines imply important variation in allocation of preventive interventions. To make informed decisions, physicians should use only the recommendations from rigorously developed guidelines.
The American Journal of Medicine, 2012
BACKGROUND: Peripheral artery disease (PAD) screening may be performed to prevent progression of ... more BACKGROUND: Peripheral artery disease (PAD) screening may be performed to prevent progression of PAD or future cardiovascular disease in general. Recommendations for PAD screening have to be derived indirectly because no randomized trials comparing screening versus no screening have been performed. We performed a systematic review of guidelines to evaluate the value of PAD screening in asymptomatic adults. national and international medical societies from Western countries, containing recommendations on PAD screening, were included. Two reviewers independently assessed rigor of guideline development using the Appraisal of Guidelines Research and Evaluation (AGREE) instrument. One reviewer performed full extraction of recommendations, which was validated by a second reviewer. RESULTS: Of 2779 titles identified, 8 guidelines were included. AGREE scores varied from 33% to 81%. Five guidelines advocated PAD screening, others found insufficient evidence for PAD screening or were against it. Measurement of the ankle-brachial index (ABI) was generally recommended for middle-aged populations with elevated cardiovascular risk levels. Those identified as having PAD are reclassified as high risk, warranting intensive preventive interventions to reduce their risk of a cardiovascular event. The underlying evidence mainly consisted of studies performed in patients with established PAD. A meta-analysis that evaluated ABI testing in the context of traditional cardiovascular risk assessment was interpreted differently. CONCLUSIONS: Recommendations on PAD screening vary across current guidelines, making the value of PAD screening uncertain. The variation seems to reflect lack of studies that show added value of detection of early PAD beyond expectant management and traditional risk assessment.
JAMA - Journal of the American Medical Association, 2010
... Nancy R. Cook, ScD ncook{at}rics.bwh.harvard.eduBrigham and Women's HospitalBoston, ... more ... Nancy R. Cook, ScD ncook{at}rics.bwh.harvard.eduBrigham and Women's HospitalBoston, Massachusetts; Karel GM Moons, MD, PhDUMC UtrechtUtrecht, the Netherlands; Frank E. Harrell, Jr ... doi:10.1373/clinchem.2009.134155, pmid:20133890. Free Full Text. 4. Harrell FE Jr. . ...
BMJ (Clinical research ed.), 2014
To evaluate differences in first manifestations of cardiovascular disease between men and women i... more To evaluate differences in first manifestations of cardiovascular disease between men and women in a competing risks framework. Prospective population based cohort study. People living in the community in Rotterdam, the Netherlands. 8419 participants (60.9% women) aged ≥ 55 and free from cardiovascular disease at baseline. First diagnosis of coronary heart disease (myocardial infarction, revascularisation, and coronary death), cerebrovascular disease (stroke, transient ischaemic attack, and carotid revascularisation), heart failure, or other cardiovascular death; or death from non-cardiovascular causes. Data were used to calculate lifetime risks of cardiovascular disease and its first incident manifestations adjusted for competing non-cardiovascular death. During follow-up of up to 20.1 years, 2888 participants developed cardiovascular disease (826 coronary heart disease, 1198 cerebrovascular disease, 762 heart failure, and 102 other cardiovascular death). At age 55, overall lifetim...