Patricia J Nelemans

Maastricht University, Maestricht, Limburg, Netherlands

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Publications (39)176.74 Total impact

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    ABSTRACT: Background: Unstable plaque characteristics on coronary CT angiography (CTA), serum high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal Pro-Brain Natriuretic Peptide (NT-proBNP) concentrations are associated with cardiovascular events. Objective: To investigate the association between coronary CTA defined quantifiable plaque characteristics, hs-cTnT and NT-proBNP. Methods: 81 consecutive stable chest pain patients with an intermediate-to-high risk were analyzed. Coronary CTA was performed using a 64-slice multidetector-row CT-scanner. Total coronary plaque volume, calcified volume, non-calcified volume, plaque burden, remodeling index (RI) and number of plaques were measured using dedicated software. A total plaque score ("Sum plaque score") incorporating total plaque volume, RI, plaque burden and number of plaques was defined. Hs-cTnT and NT-proBNP concentrations were measured in serum samples before coronary CTA. Results: Univariate regression analysis demonstrated significant associations of hs-cTnT and NT-proBNP with total plaque volume (r hs-cTnT = .256; r NT-proBNP = .270), calcified volume (r hs-cTnT = .344; r NT-proBNP = .344), RI (r hs-cTnT = .335; r NT-proBNP = .342) and number of plaques (r hs-cTnT = .355; r NT-proBNP = .301) (all P values ≤ .021). Non-calcified plaque volume showed no association with hs-cTnT and NT-proBNP (r hs-cTnT = .050; r NT-proBNP = .087; P value = .660 and P value = .442). The "Sum plaque score" showed the highest correlation compared to other plaque parameters (r hs-cTnT = .362; r NT-proBNP = .409; P value = .001 and P value ≤ .001). Conclusion: Our data suggest that coronary plaque morphology parameters, derived by dedicated software, are associated with serum hs-cTnT and NT-proBNP concentrations.
    Full-text · Article · Oct 2015 · Journal of cardiovascular computed tomography
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    ABSTRACT: Objectives: To analyse predictors for short- and long-term renal function changes after fenestrated and branched endovascular aortic repair (EVAR). Methods: A total of 157 patients underwent fenestrated and branched EVAR. Procedural intra-arterial iodinated contrast volume was documented. Serum creatinine and estimated glomerular filtration rate (eGFR) at baseline, during 48 h following EVAR, at discharge and latest moment of follow-up were recorded. Development of post-EVAR acute kidney injury (AKI; according to AKIN criteria), and potential risk factors for renal failure were recorded. Multivariate regression analyses were used to identify independent risk factors for AKI and eGFR decrease during follow-up. Results: Forty-three patients (28 %) developed post-EVAR AKI. Long procedure time and occlusion of accessory renal arteries were independent risk factors for development of AKI. (odds ratio (OR) 1.005 per minute, 95 % CI 1.001-1.01; p = 0.025 and OR 3.02, 95 % CI 1.19-8.16; p = 0.029). Post-EVAR AKI was associated with a significantly increased risk for eGFR decrease at discharge and latest follow-up (hazard ratio (HR) 3.47, 95 % CI 1.63-7.36, p = 0.001 and HR 3.01, 95 % CI 1.56-5.80; p = 0.001). Iodinated contrast volume was not an independent risk factor for AKI or eGFR decrease during follow-up. Conclusion: Development of post-EVAR AKI is an independent risk factor for long-term renal function decrease. Key points: • Longer procedure time is associated with an increased risk for AKI. • Renal perfusion defects on angiography are associated with increased risk for AKI. • Post-EVAR AKI is associated with higher probability for long-term eGFR decrease. • Iodinated contrast volume is not an independent risk factor for AKI. • Iodinated contrast volume is not an independent risk factor for long-term eGFR decrease.
    Preview · Article · Oct 2015 · European Radiology
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    ABSTRACT: Purpose: To assess and quantify the magnitude and direction of respiratory movement of the aorta and origins of its side branches. Methods: A quantitative 3-dimensional (3D) subtraction analysis of computed tomography (CT) scans during inspiration and expiration was performed to determine the respiratory geometric movements of the aorta and side branches in 60 patients. During breath-hold expiration and inspiration, 1-mm-thick CT slices of the aorta were acquired in unenhanced and contrast-enhanced scans. The datasets were compared using dedicated multiplanar reformation image subtraction software to determine the change in position of relevant anatomic sections, including the ascending thoracic aorta (AA), the origins of the brachiocephalic artery (BA) and left subclavian artery (LSA), the descending thoracic aorta (DTA) at the level of the tenth thoracic vertebra, as well as the origins of the celiac trunk, superior mesenteric artery, and the renal arteries. Results: Complex movement was visible during inspiration; the regions of interest in the thoracic aorta and side branches moved in the anterior, medial, and caudal directions compared with the expiration state. Mean 3D movement vectors (± standard deviation) were 8.9±3.6 mm (AA), 12.0±4.1 mm (BA), 11.1±3.9 mm (LSA), and 4.9±2.5 mm (DTA). Abdominal side branches moved in the caudal direction 1.3±1.1 mm. There was significantly less movement in the DTA compared to AA (p<0.001). The correlation coefficient between the extent of LSA movement and thoracic excursion was 0.78. Conclusion: The aorta and side branches undergo considerable respiratory movement. The results from this study provide an important contribution to understanding aortic dynamics.
    No preview · Article · Sep 2015 · Journal of Endovascular Therapy
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    ABSTRACT: Purpose: To evaluate the diagnostic performance of unenhanced axillary T2-weighted and diffusion-weighted (DW) magnetic resonance (MR) imaging for axillary nodal staging in patients with newly diagnosed breast cancer, with node-by-node and patient-by-patient validation. Materials and methods: Institutional review board approval and informed consent were obtained. Fifty women (mean age, 60 years; range, 22-80 years) underwent high-spatial-resolution axillary 3.0-T T2-weighted imaging without fat suppression and DW imaging (b = 0, 500, and 800 sec/mm(2)), followed by either sentinel lymph node biopsy (SLNB) or axillary lymph node dissection. Two radiologists independently scored each lymph node on a confidence level scale from 0 (benign) to 4 (malignant), first on T2-weighted MR images, then on DW MR images. Two researchers independently measured the mean apparent diffusion coefficient (ADC) of each lymph node. Diagnostic performance parameters were calculated on the basis of node-by-node and patient-by-patient validation. Results: With respective node-by-node and patient-by-patient validation, T2-weighted MR imaging had a specificity of 93%-97% and 87%-95%, sensitivity of 32%-55% and 50%-67%, negative predictive value (NPV) of 88%-91% and 86%-89%, positive predictive value (PPV) of 60%-70% and 62%-75%, and area under the receiver operating characteristic curve (AUC) of 0.78 and 0.80-0.88, with good interobserver agreement (κ = 0.70). The addition of DW MR imaging resulted in lower specificity (59%-88% and 50%-84%), higher sensitivity (45%-64% and 75%-83%), comparable NPV (89% and 90%-91%), lower PPV (23%-42% and 34%-60%), and lower AUC (0.68-0.73 and 0.70-0.86). ADC measurement resulted in a specificity of 63%-64% and 61%-63%, sensitivity of 41% and 67%, NPV of 85% and 85%-86%, PPV of 18% and 35%-36%, and AUC of 0.54-0.58 and 0.69-0.74, respectively, with excellent interobserver agreement (intraclass correlation coefficient, 0.83). Conclusion: Dedicated high-spatial-resolution axillary T2-weighted MR imaging showed good specificity on the basis of node-by-node and patient-by-patient validation, with good interobserver agreement. However, its NPV is still insufficient to substitute it for SLNB for exclusion of axillary lymph node metastasis. DW MR imaging and ADC measurement were of no added value.
    Full-text · Article · Dec 2014 · Radiology
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    ABSTRACT: Purpose: This study was designed to evaluate the feasibility of endovascular guidance by means of live fluoroscopy fusion with magnetic resonance angiography (MRA) and computed tomography angiography (CTA). Methods: Fusion guidance was evaluated in 20 endovascular peripheral artery interventions in 17 patients. Fifteen patients had received preinterventional diagnostic MRA and two patients had undergone CTA. Time for fluoroscopy with MRA/CTA coregistration was recorded. Feasibility of fusion guidance was evaluated according to the following criteria: for every procedure the executing interventional radiologists recorded whether 3D road-mapping provided added value (yes vs. no) and whether PTA and/or stenting could be performed relying on the fusion road-map without need for diagnostic contrast-enhanced angiogram series (CEAS) (yes vs. no). Precision of the fusion road-map was evaluated by recording maximum differences between the position of the vasculature on the virtual CTA/MRA images and conventional angiography. Results: Average time needed for image coregistration was 5 ± 2 min. Three-dimensional road-map added value was experienced in 15 procedures in 12 patients. In half of the patients (8/17), intervention was performed relying on the fusion road-map only, without diagnostic CEAS. In two patients, MRA roadmap showed a false-positive lesion. Excluding three patients with inordinate movements, mean difference in position of vasculature on angiography and MRA/CTA road-map was 1.86 ± 0.95 mm, implying that approximately 95 % of differences were between 0 and 3.72 mm (2 ± 1.96 standard deviation). Conclusions: Fluoroscopy with MRA/CTA fusion guidance for peripheral artery interventions is feasible. By reducing the number of CEAS, this technology may contribute to enhance procedural safety.
    Full-text · Article · Jul 2014 · CardioVascular and Interventional Radiology
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    ABSTRACT: Purpose Epicardial adipose tissue (EAT) is emerging as a risk factor for coronary artery disease (CAD). The aim of this study was to determine the applicability and efficiency of automated EAT quantification. Methods and Materials EAT volume was assessed both manually and automatically in 157 coronary CTA patients. Manual assessment consisted of a short axis-based manual measurement while automated assessment on both contrast and non-contrast enhanced datasets was achieved through novel prototype software (syngo.via, Siemens Healthcare). Duration of both quantification methods was recorded and EAT volumes were compared using paired samples t-test. Correlation of volumes was determined using intraclass correlation coefficient; agreement was tested using Bland-Altman analysis. The association between EAT and CAD was estimated using logistic regression. Results Automated quantification was significantly less time consuming than automated quantification (17±2 vs. 280±78 seconds, p<0.0001). Although manual EAT volume differed significantly from automated EAT volume (75±33 cm³ vs. 95±45 cm³, p<0.001), a good correlation between both assessments was found (r=0.76, p<0.001). For all methods, EAT volume was positively associated with the presence of CAD. Stronger predictive value for the severity of CAD was achieved through automated quantification on both contrast enhanced and non-contrast enhanced datasets. Conclusion Automated EAT quantification is a quick method to estimate EAT and may serve as a predictor for CAD presence and severity.
    No preview · Article · May 2014 · Journal of Cardiovascular Computed Tomography
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    ABSTRACT: The aim of this study was to evaluate the sensitivity and specificity of MR angiography (MRA) in the diagnosis of ruptured and unruptured intracranial aneurysms. A systematic search was performed on 4 electronic databases on relevant articles that were published from January 1998 to October 2013. Inclusion criteria were met by 12 studies that compared MRA with digital subtraction angiography as reference standard. Two independent reviewers evaluated the methodological quality of the studies. Data from eligible studies were extracted and used to construct 2×2 contingency tables on a per-aneurysm level. Pooled estimates of sensitivity and specificity were calculated for all studies and subgroups of studies. Heterogeneity was tested, and risk for publication bias was assessed. Included studies were of high methodological quality. Studies with larger sample size tended to have higher diagnostic performance. Most studies used time-of-flight MRA technique. Among the 960 patients assessed, 772 aneurysms were present. Heterogeneity with reference to sensitivity and specificity was moderate to high. Pooled sensitivity of MRA was 95% (95% confidence interval, 89%-98%), and pooled specificity was 89% (95% confidence interval, 80%-95%). False-negative and false-positive aneurysms detected on MRA were mainly located at the skull base and middle cerebral artery. Freehand 3-dimensional reconstructions performed by the radiologist significantly increased diagnostic performance. Studies performed on 3 Tesla showed a trend toward higher performance (P=0.054). Studies on diagnostic performance of MRA show high sensitivity with large variation in specificity in the detection of intracranial aneurysms.
    Preview · Article · Dec 2013 · Stroke
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    ABSTRACT: Although electrocardiography is frequently used as an initial test to detect or rule out previous myocardial infarction (MI), the diagnostic performance of commonly used electrocardiographic scoring systems is not well described. We aimed to determine the diagnostic accuracy of (1) the Universal Definition, (2) Minnesota ECG Code (MC), (3) Selvester QRS Score, and (4) assessment by cardiologists using late gadolinium enhancement cardiovascular magnetic resonance imaging as the reference standard. Additionally, the effect of electrocardiographic patterns and infarct characteristics on detecting previous MI was evaluated. The 3-month follow-up electrocardiograms of 78 patients with first-time reperfused ST elevation MI were pooled with electrocardiograms of 36 healthy controls. All 114 electrocardiograms were randomly analyzed, blinded to clinical and LGE-CMR data. The sensitivity of the Universal Definition, MC, Selvester QRS Score, and cardiologists to detect previous MI was 33%, 79%, 90%, and 67%, respectively; specificity 97%, 72%, 31%, and 89%, respectively; diagnostic accuracy 54%, 77%, 71%, and 74%, respectively. Probability of detecting MI by cardiologists increased with an increasing number (odds ratio [OR] 2.00, 95% confidence interval [CI] 1.30 to 3.09), width (OR 1.02, 95% CI 1.01 to 1.03), and depth (OR 1.16, 95% CI 1.07 to 1.27) of Q waves as well as increasing infarct size (OR 1.15, 95% CI 1.06 to 1.25) and transmurality (OR 1.05, 95% CI 1.01 to 1.08; p <0.05 for all). The time-consuming MC and rapid visual assessment by cardiologists achieved the best and similar diagnostic accuracies to detect previous MI. The diagnostic performance of all 4 electrocardiographic scoring systems was modest and related to the number, depth, and width of Q waves as well as increasing infarct size and transmurality. In conclusion, the exclusion of a previous MI based solely on electrocardiographic findings should be done with caution. Future studies are needed to define which patients should be referred to additional diagnostic testing.
    No preview · Article · Jul 2013 · The American journal of cardiology
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    ABSTRACT: Background As one of the primary etiologies of the post-thrombotic syndrome, chronic venous occlusion is a huge burden on patient quality of life and medical costs. In this study, we evaluate the short-term and midterm results of endovenous recanalization by angioplasty and stenting in chronic iliofemoral deep venous occlusions. Methods This is a retrospective observational study set in a tertiary medical referral center. Patients with venous claudication or C4-6 venous disease combined with duplex and magnetic resonance-confirmed iliofemoral or caval occlusion were included. Patients with recent deep vein thrombosis (<1 year) were excluded. The intervention was endovascular deep venous recanalization, followed by angioplasty and stenting. Safety and feasibility were clinically evaluated during the procedure and during follow-up. Reocclusions and other treatment failures were evaluated during a maximum follow-up of 31 months by ultrasound imaging and venography. Results Seventy-five procedures were performed in 63 patients (average age, 44 years; range, 18-75 years), of whom 86% had a history of deep venous thrombosis. The mean time between the initial deep venous thrombosis and treatment with PTA and stenting was 12 years (maximum, 31 years). May-Thurner syndrome was present in 57%. Forty-two procedures were performed in the left, six in the right, and 11 in both lower extremities. The vena cava inferior was partially stented in 25 patients. An average of 2.6 stents (median, 2) were used per procedure. Primary patency was 74% after 1 year. Assisted primary and secondary patency rates were 81% and 96%, respectively, at 1 year. Secondary procedures included restenting, catheter-directed thrombolysis, endophlebectomy of the common femoral vein, and creation of an arteriovenous fistula. No clinically evident pulmonary emboli were noted. A bleeding complication occurred after six procedures and was deemed major in two. No patients died. Relief or significant improvement of symptoms of chronic venous occlusive disease was achieved in 81% of patients. Conclusions Endovenous recanalization by angioplasty and stenting of chronically occluded iliofemoral vein segments is a safe and effective treatment with good short-term results, even when treatment takes place decades after the initial deep venous thrombosis. Most reocclusions can be adequately treated by a secondary procedure.
    Full-text · Article · Apr 2013
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    Full-text · Article · Jan 2013 · Journal of Cardiovascular Magnetic Resonance
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    ABSTRACT: Background Although echocardiography is used as a first line imaging modality, its accuracy to detect acute and chronic myocardial infarction (MI) in relation to infarct characteristics as assessed with late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) is not well described. Methods One-hundred-forty-one echocardiograms performed in 88 first acute ST-elevation MI (STEMI) patients, 2 (IQR1-4) days (n = 61) and 102 (IQR92-112) days post-MI (n = 80), were pooled with echocardiograms of 36 healthy controls. 61 acute and 80 chronic echocardiograms were available for analysis (53 patients had both acute and chronic echocardiograms). Two experienced echocardiographers, blinded to clinical and CMR data, randomly evaluated all 177 echocardiograms for segmental wall motion abnormalities (SWMA). This was compared with LGE-CMR determined infarct characteristics, performed 104 ± 11 days post-MI. Enhancement on LGE-CMR matched the infarct-related artery territory in all patients (LAD 31%, LCx 12% and RCA 57%). Results The sensitivity of echocardiography to detect acute MI was 78.7% and 61.3% for chronic MI; specificity was 80.6%. Undetected MI were smaller, less transmural, and less extensive (6% [IQR3-12] vs. 15% [IQR9-24], 50 ± 14% vs. 61 ± 15%, 7 ± 3 vs. 9 ± 3 segments, p < 0.001 for all) and associated with higher left ventricular ejection fraction (LVEF) and non-anterior location as compared to detected MI (58 ± 5% vs. 46 ± 7%, p < 0.001 and 82% vs. 63%, p = 0.03). After multivariate analysis, LVEF and infarct size were the strongest independent predictors of detecting chronic MI (OR 0.78 [95%CI 0.68-0.88], p < 0.001 and OR 1.22 [95%CI0.99-1.51], p = 0.06, respectively). Increasing infarct transmurality was associated with increasing SWMA (p < 0.001). Conclusions In patients presenting with STEMI, and thus a high likelihood of SWMA, the sensitivity of echocardiography to detect SWMA was higher in the acute than the chronic phase. Undetected MI were smaller, less extensive and less transmural, and associated with non-anterior localization and higher LVEF. Further work is needed to assess the diagnostic accuracy in patients with non-STEMI.
    Full-text · Article · Jan 2013 · Journal of Cardiovascular Magnetic Resonance
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    ABSTRACT: Both end-stage and milder stages of chronic kidney disease (CKD) are associated with an increased risk of adverse cardiovascular events. Several studies found an association between decreasing renal function and increasing coronary artery calcification, but it remains unclear if this association is independent from traditional cardiovascular risk factors. Therefore, the aim of this study was to investigate whether mild to moderate CKD is independently associated with coronary plaque burden beyond traditional cardiovascular risk factors.
    Full-text · Article · Oct 2012 · PLoS ONE
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    ABSTRACT: This study aimed to determine the diagnostic accuracy of the 3 most commonly used noninvasive myocardial perfusion imaging modalities, single-photon emission computed tomography (SPECT), cardiac magnetic resonance (CMR), and positron emission tomography (PET) perfusion imaging for the diagnosis of obstructive coronary artery disease (CAD). Additionally, the effect of test and study characteristics was explored. Accurate detection of obstructive CAD is important for effective therapy. Noninvasive myocardial perfusion imaging is increasingly being applied to gauge the severity of CAD. Studies published between 1990 and 2010 identified by PubMed search and citation tracking were examined. A study was included if a perfusion imaging modality was used as a diagnostic test for the detection of obstructive CAD and coronary angiography as the reference standard (≥50% diameter stenosis). Of the 3,635 citations, 166 articles (n = 17,901) met the inclusion criteria: 114 SPECT, 37 CMR, and 15 PET articles. There were not enough publications on other perfusion techniques such as perfusion echocardiography and computed tomography to include these modalities into the study. The patient-based analysis per imaging modality demonstrated a pooled sensitivity of 88% (95% confidence interval [CI]: 88% to 89%), 89% (95% CI: 88% to 91%), and 84% (95% CI: 81% to 87%) for SPECT, CMR, and PET, respectively; with a pooled specificity of 61% (95% CI: 59% to 62%), 76% (95% CI: 73% to 78%), and 81% (95% CI: 74% to 87%). This resulted in a pooled diagnostic odds ratio (DOR) of 15.31 (95% CI: 12.66 to 18.52; I(2) 63.6%), 26.42 (95% CI: 17.69 to 39.47; I(2) 58.3%), and 36.47 (95% CI: 21.48 to 61.92; I(2) 0%). Most of the evaluated test and study characteristics did not affect the ranking of diagnostic performances. SPECT, CMR, and PET all yielded a high sensitivity, while a broad range of specificity was observed. SPECT is widely available and most extensively validated; PET achieved the highest diagnostic performance; CMR may provide an alternative without ionizing radiation and a similar diagnostic accuracy as PET. We suggest that referring physicians consider these findings in the context of local expertise and infrastructure.
    Full-text · Article · May 2012 · Journal of the American College of Cardiology
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    ABSTRACT: Epicardial adipose tissue (EAT) volume has been associated with coronary artery disease (CAD). As diabetes mellitus type 2 (DM2) patients have higher EAT volumes, it has been suggested that EAT may play a role in promoting CAD in these patients. The aim of this study was to examine the association between EAT and CAD in DM2, impaired fasting glucose (IFG) and control patients presenting with stable chest pain. A total of 410 stable chest pain patients underwent multidetector cardiac computed tomography angiography (CCTA) to assess the presence of CAD. The extent of CAD was expressed as the number of affected segments. The EAT volume was measured using three-dimensional volumetric quantification. The EAT was compared using ANOVA, logistic and linear regression models were used to assess its predictive value. Multivariable regression analysis corrected for traditional risk factors was performed. Eighty-three patients had DM2, 118 IFG and there were 209 controls. DM2 as well as IFG patients had higher EAT volumes compared with controls (98 ± 41, 92 ± 39, and 75 ± 34 cm(3), respectively; P < 0.001). EAT predicted the presence (OR: 1.01; P < 0.001) and the extent of CAD (B: 0.01; P < 0.001). The associations were equal in all subgroups. However, in a multivariable regression model corrected for traditional cardiovascular risk factors, EAT was not an independent predictor for the presence or extent of CAD (OR: 1.00; P = 0.88 and B: -0.11; P = 0.68, respectively). The EAT volume is associated with CAD in DM2, IFG, and control patients. However, EAT is not an independent predictor for CAD in patients presenting with stable chest pain.
    Full-text · Article · Feb 2012 · European Heart Journal Cardiovascular Imaging
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    Full-text · Article · Feb 2012 · Journal of Cardiovascular Magnetic Resonance
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    Full-text · Article · Feb 2011 · Journal of Cardiovascular Magnetic Resonance
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    ABSTRACT: Poor adherence to treatment is one of the major problems in the treatment of hypertension. Self blood pressure measurement may help patients to improve their adherence to treatment. In this prospective, randomized, controlled study coordinated by a university hospital, a total of 228 mild-to-moderate hypertensive patients were randomized to either a group that performed self-measurements at home in addition to office blood pressure measurements [the self-pressure group (n = 114)] or a group that only underwent office blood pressure measurement [the office pressure group (n = 114)]. Patients were followed for 1 year in which treatment was adjusted, if necessary, at each visit to the physician's office according to the achieved blood pressure. Adherence to treatment was assessed by means of medication event monitoring system TrackCaps. Median adherence was slightly greater in patients from the self-pressure group than in those from the office pressure group (92.3 vs. 90.9%; P = 0.043). Although identical among both groups, in the week directly after each visit to the physician's office, adherence [71.4% (interquartile range 71-79%)] was significantly lower (P < 0.001) than that at the last 7 days prior to each visit [100% (interquartile range 90-100%)]. On the remaining days between the visits, patients from the self-pressure group displayed a modestly better adherence than patients from the office pressure group (97.6 vs. 97.0%; P = 0.024). Although self-blood pressure measurement as an adjunct to office blood pressure measurement led to somewhat better adherence to treatment in this study, the difference was only small and not clinically significant. The time relative to a visit to the doctor seems to be a more important predictor of adherence.
    Full-text · Article · Nov 2009 · Journal of Hypertension
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    ABSTRACT: This article investigates whether differences in utility scores based on the EQ-5D and the SF-6D have impact on the incremental cost-utility ratios in five distinct patient groups. We used five empirical data sets of trial-based cost-utility studies that included patients with different disease conditions and severity (musculoskeletal disease, cardiovascular pulmonary disease, and psychological disorders) to calculate differences in quality-adjusted life-years (QALYs) based on EQ-5D and SF-6D utility scores. We compared incremental QALYs, incremental cost-utility ratios, and the probability that the incremental cost-utility ratio was acceptable within and across the data sets. We observed small differences in incremental QALYs, but large differences in the incremental cost-utility ratios and in the probability that these ratios were acceptable at a given threshold, in the majority of the presented cost-utility analyses. More specifically, in the patient groups with relatively mild health conditions the probability of acceptance of the incremental cost-utility ratio was considerably larger when using the EQ-5D to estimate utility. While in the patient groups with worse health conditions the probability of acceptance of the incremental cost-utility ratio was considerably larger when using the SF-6D to estimate utility. Much of the appeal in using QALYs as measure of effectiveness in economic evaluations is in the comparability across conditions and interventions. The incomparability of the results of cost-utility analyses using different instruments to estimate a single index value for health severely undermines this aspect and reduces the credibility of the use of incremental cost-utility ratios for decision-making.
    Full-text · Article · Oct 2009 · Value in Health
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    ABSTRACT: Het doel van deze literatuurstudie is om de effectiviteit na te gaan van intensieve huisbezoekenprogramma's aan ouderen met gezondheidsproblemen of functionele beperkingen. Het doorzoeken van de literatuur was gebaseerd op de ingesloten experimenten van vier literatuurstudies over de effectiviteit van huisbezoeken, gepubliceerd vanaf 2000, en de databestanden van Cinahl, Cochrane, Embase, Medline en PsycINFO vanaf 2001. De zoekstrategie identificeerde 844 studies, waarvan acht voldeden aan de inclusiecriteria. Zeven experimenten waren van voldoende methodologische kwaliteit; geen van deze experimenten hadden, op basis van de belangrijkste analyses, een significant gunstig effect voor de interventiegroep in vergelijking met de controlegroep op mortaliteit, gezondheid, zorggebruik of kosten. De inclusie van minder intensieve programma's voor kwetsbare ouderen zou weinig invloed uitgeoefend hebben op de conclusies van onze literatuurstudie. We concluderen dat huisbezoekenprogramma's niet zinvol lijken voor oudere personen met (ervaren) gezondheidsproblemen binnen het gezondheidszorgsysteem van westerse landen.
    Full-text · Article · Apr 2009 · Tijdschrift voor Verpleeghuisgeneeskunde
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    ABSTRACT: The objective of this study was to assess compliance with a 10-day treatment of antibiotics or placebo once-daily (OD) and three-times-daily (TD) for lower respiratory tract infections (LRTIs) using electronic monitoring, and to evaluate whether compliance depends on time since the start of treatment and weekday. Taking compliance, timing compliance, correct dosing compliance and mean interdose intervals were assessed using data from 155 LRTI patients who received either a 10-day treatment of amoxicillin TD and placebo OD or roxithromycin OD and placebo TD using a double-dummy technique. Compliance was assessed by electronic monitoring. Taking compliance was 98.0% for the OD regimen and 91.0% for the TD regimen. Correct dosing was 98.1% for the OD regimen and 91.1% for the TD regimen and timing compliance was 48.2% and 10.9%, respectively. The mean interdose interval before the first daily dose for the TD group was particularly prolonged to >13h. Correct dosing over time showed fewer patients with correct dosing compliance, reaching a low of 79% for the TD group towards the end of the 10-day treatment. Compliance was not influenced by weekday. This study adds important information to the limited evidence on compliance with antibiotics for LRTI, one of the most common reasons for consultation in primary care. Taking compliance was high for both regimens, yet timing compliance was poor. The prolonged mean interdose intervals provide striking new insights into understanding non-compliance with more-than-once-daily regimens. These findings require consideration when exploring ways to improve future compliance in short-term antibiotic treatment for respiratory tract infections.
    Full-text · Article · Jun 2008 · International Journal of Antimicrobial Agents

Publication Stats

1k Citations
176.74 Total Impact Points

Institutions

  • 2000-2015
    • Maastricht University
      • • Department of Epidemiology
      • • Department of Radiology
      Maestricht, Limburg, Netherlands
  • 2012-2013
    • Maastricht Universitair Medisch Centrum
      • Central Diagnostic Laboratory
      Maestricht, Limburg, Netherlands
  • 2005
    • Leiden University
      Leyden, South Holland, Netherlands