Sandra Spronk

Systematic Review of Guidelines on Cardiovascular Risk Assessment: Which Recommendations Should Clinicians Follow for a Cardiovascular Health Check?

OBJECTIVE To appraise guidelines on cardiovascular risk assessment to guide selection of screening interventions for a health check. DATA SOURCES 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. STUDY SELECTION 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. DATA EXTRACTION Rigor of guideline development was assessed by 2 independent reviewers. One reviewer extracted information on conflicts of interest and recommendations. RESULTS 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. CONCLUSIONS 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.

Intermittent Claudication: Clinical Effectiveness of Endovascular Revascularization versus Supervised Hospital-based Exercise Training—Randomized Controlled Trial

PURPOSE To compare clinical success, functional capacity, and quality of life during 12 months after revascularization or supervised exercise training in patients with intermittent claudication. MATERIALS AND METHODS This study had institutional review board approval, and all patients gave written informed consent. Between September 2002 and September 2005, 151 consecutive patients who presented with symptoms of intermittent claudication were randomly assigned to undergo either endovascular revascularization (angioplasty-first approach) (n = 76) or hospital-based supervised exercise (n = 75). The outcome measures were clinical success, functional capacity, and quality of life after 6 and 12 months. Clinical success was defined as improvement in at least one category in the Rutherford scale above the pretreatment level. Significance of differences between the groups was assessed with the unpaired t test, chi(2) test, or Mann-Whitney U test. To adjust outcomes for imbalances of baseline values, multivariable regression analysis was performed. RESULTS Immediately after the start of treatment, patients who underwent revascularization improved more than patients who performed exercise in terms of clinical success (adjusted odds ratio [OR], 39; 99% confidence interval [CI]: 11, 131; P < .001), but this advantage was lost after 6 (adjusted OR, 0.9; 99% CI: 0.3, 2.3; P = .70) and 12 (adjusted OR, 1.1; 99% CI: 0.5, 2.8; P = .73) months. After revascularization, fewer patients showed signs of ipsilateral symptoms at 6 months compared with patients in the exercise group (adjusted OR, 0.4; 99% CI: 0.2, 0.9; P < .001), but no significant differences were demonstrated at 12 months. After both treatments, functional capacity and quality of life scores increased after 6 and 12 months, but no significant differences between the groups were demonstrated. CONCLUSION After 6 and 12 months, patients with intermittent claudication benefited equally from either endovascular revascularization or supervised exercise. Improvement was, however, more immediate after revascularization.

Cost-effectiveness of endovascular revascularization compared to supervised hospital-based exercise training in patients with intermittent claudication: A randomized controlled trial

BACKGROUND The optimal first-line treatment for intermittent claudication is currently unclear. OBJECTIVE To compare the cost-effectiveness of endovascular revascularization vs supervised hospital-based exercise in patients with intermittent claudication during a 12-month follow-up period. DESIGN Randomized controlled trial with patient recruitment between September 2002-September 2006 and a 12-month follow-up per patient. SETTING A large community hospital. PARTICIPANTS Patients with symptoms of intermittent claudication due to an iliac or femoro-popliteal arterial lesion (293) who fulfilled the inclusion criteria (151) were recruited. Excluded were, for example, patients with lesions unsuitable for revascularization (iliac or femoropopliteal TASC-type D and some TASC type-B/C. INTERVENTION Participants were randomly assigned to endovascular revascularization (76 patients) or supervised hospital-based exercise (75 patients). MEASUREMENTS Mean improvement of health-related quality-of-life and functional capacity over a 12-month period, cumulative 12-month costs, and incremental costs per quality-adjusted life year (QALY) were assessed from the societal perspective. RESULTS In the endovascular revascularization group, 73% (55 patients) had iliac disease vs 27% (20 patients) femoral disease. Stents were used in 46/71 iliac lesions (34 patients) and in 20/40 femoral lesions (16 patients). In the supervised hospital-based exercise group, 68% (51 patients) had iliac disease vs 32% (24 patients) with femoral disease. There was a non-significant difference in the adjusted 6- and 12-month EuroQol, rating scale, and SF36-physical functioning values between the treatment groups. The gain in total mean QALYs accumulated during 12 months, adjusted for baseline values, was not statistically different between the groups (mean difference revascularization versus exercise 0.01; 99% CI -0.05, 0.07; P = .73). The total mean cumulative costs per patient was significantly higher in the revascularization group (mean difference euro2318; 99% CI 2130 euros, 2506 euros; P < .001) and the incremental cost per QALY was 231 800 euro/QALY adjusted for the baseline variables. One-way sensitivity analysis demonstrated improved effectiveness after revascularization (mean difference 0.03; CI 0.02, 0.05; P < .001), making the incremental costs 75 208 euro/QALY. CONCLUSION In conclusion, there was no significant difference in effectiveness between endovascular revascularization compared to supervised hospital-based exercise during 12-months follow-up, any gains with endovascular revascularization found were non-significant, and endovascular revascularization costs more than the generally accepted threshold willingness-to-pay value, which favors exercise.

Methods for Calculating Sensitivity and Specificity of Clustered Data: A Tutorial

UNLABELLED The performance of a diagnostic test is often expressed in terms of sensitivity and specificity compared with the reference standard. Calculations of sensitivity and specificity commonly involve multiple observations per patient, which implies that the data are clustered. Whether analysis of sensitivity and specificity per patient or using multiple observations per patient is preferable depends on the clinical context and consequences. The purpose of this article was to discuss and illustrate the most common statistical methods that calculate sensitivity and specificity of clustered data, adjusting for the possible correlation between observations within each patient. This tutorial presents and illustrates the following methods: (a) analysis at different levels ignoring correlation, (b) variance adjustment, (c) logistic random-effects models, and (d) generalized estimating equations. The choice of method and the level of reporting should correspond with the clinical decision problem. If multiple observations per patient are relevant to the clinical decision problem, the potential correlation between observations should be explored and taken into account in the statistical analysis. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120509/-/DC1.

Comparative effectiveness and cost-effectiveness of computed tomography screening for coronary artery calcium in asymptomatic individuals

OBJECTIVES The aim of this study was to assess the (cost-) effectiveness of screening asymptomatic individuals at intermediate risk of coronary heart disease (CHD) for coronary artery calcium with computed tomography (CT). BACKGROUND Coronary artery calcium on CT improves prediction of CHD. METHODS A Markov model was developed on the basis of the Rotterdam Study. Four strategies were evaluated: 1) current practice; 2) current prevention guidelines for cardiovascular disease; 3) CT screening for coronary calcium; and 4) statin therapy for all individuals. Asymptomatic individuals at intermediate risk of CHD were simulated over their remaining lifetime. Quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios were calculated. RESULTS In men, CT screening was more effective and more costly than the other 3 strategies (CT vs. current practice: +0.13 QALY [95% confidence interval (CI): 0.01 to 0.26], +

Systematic review of guidelines on imaging of asymptomatic coronary artery disease.

4,676 [95% CI:

Supervised walking therapy in patients with intermittent claudication.

3,126 to

Systematic review of guidelines on abdominal aortic aneurysm screening

6,339]; CT vs. statin therapy: +0.04 QALY [95% CI: -0.02 to 0.13], +

Systematic Review of Guidelines on Peripheral Artery Disease Screening

1,951 [95% CI:

Efficacy of biological agents in juvenile idiopathic arthritis: a systematic review using indirect comparisons

1,170 to