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Purpose: Different health state utility (HSU) instruments produce different utilities for the same individuals, thereby compromising the intended comparability of economic evaluations of health care interventions. When developing crosswalks, previous studies have indicated nonlinear relationships. This paper inquires into the degree of nonlinearity across the four most widely used HSU-instruments and proposes exchange rates that differ depending on the severity levels of the health state utility scale.Methods: Overall, 7933 respondents from six countries, 1760 in a non-diagnosed healthy group and 6173 in seven disease groups, reported their health states using four different instruments: EQ-5D-5L, SF-6D, HUI-3 and 15D. Quantile regressions investigate the degree of nonlinear relationships between these instruments. To compare the instruments across different disease severities, we split the health state utility scale into utility intervals with 0.2 successive decrements in utility starting from perfect health at 1.00. Exchange rates (ERs) are calculated as the mean utility difference between two utility intervals on one HSU-instrument divided by the difference in mean utility on another HSU-instrument.Results: Quantile regressions reveal significant nonlinear relationships across all four HSU-instruments. The degrees of nonlinearities differ, with a maximum degree of difference in the coefficients along the health state utility scale of 3.34 when SF-6D is regressed on EQ-5D. At the lower end of the health state utility scale, the exchange rate from SF-6D to EQ-5D is 2.11, whilst at the upper end it is 0.38.Conclusion: Comparisons at different utility levels illustrate the fallacy of using linear functions as crosswalks between HSU-instruments. The existence of nonlinear relationships between different HSU-instruments suggests that level-specific exchange rates should be used when converting a change in utility on the instrument used, onto a corresponding utility change had another instrument been used. Accounting for nonlinearities will increase the validity of the comparison for decision makers when faced with a choice between interventions whose calculations of QALY gains have been based on different HSU-instruments. [ABSTRACT FROM AUTHOR]

Background and Aims: Although much has been written about the conventional cardiovascular risk factor correlates of the extent of coronary artery calcification (CAC), few studies have been carried out on symptomatic patients. This paper assesses the potential ability of risk factors to associate with an increasing CAC score.Methods: From the European Calcific Coronary Artery Disease (Euro-CCAD) cohort, we retrospectively investigated 6309 symptomatic patients, 62% male, from Denmark, France, Germany, Italy, Spain and the USA. All had conventional cardiovascular risk factor assessment and CT scanning for CAC scoring.Results: Among all patients, male sex (OR = 4.85, p<0.001) and diabetes (OR = 2.36, p<0.001) were the most important risk factors of CAC extent, with age, hypertension, dyslipidemia and smoking also showing a relationship. Among patients with CAC, age, diabetes, hypertension and dyslipidemia were associated with an increasing CAC score in males and females, with diabetes being the strongest dichotomous risk factor (p<0.001 for both). These results were echoed in quantile regression, where diabetes was consistently the most important correlate with CAC extent in every quantile in both males and females. To a lesser extent, hypertension and dyslipidemia were also associated in the high CAC quantiles and the low CAC quantiles respectively.Conclusion: In addition to age and male sex in the total population, diabetes is the most important correlate of CAC extent in both sexes. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the safety and effectiveness of primary stenting of the common (CIA) or external iliac artery (EIA) using the Visi-Pro Balloon-Expandable Peripheral Stent System for treatment of stenotic, restenotic, or occluded lesions.Methods: Between 2011 and 2012, 75 patients (mean age 64.2±8.9 years; 46 men) with Rutherford category 2-4 ischemia and atherosclerotic lesions ≤10 cm in length underwent iliac artery stenting at 17 centers in the United States and Europe. The primary outcome of the study was the major adverse event (MAE) rate at 9 months postprocedure [composite of periprocedural death, in-hospital myocardial infarction, clinically driven target lesion revascularization (CD-TLR), and amputation of the treated limb]. Secondary outcomes included 30-day MAE rate, 9-month primary patency, changes in ankle-brachial index (ABI) and the Walking Impairment Questionnaire at 30 days and 9 months postprocedure, device success, and clinically driven target vessel revascularization (CD-TVR) at 30 days and 9 months. Outcomes in specific patient cohorts (ie, gender, stent location, calcification severity, and lesion grade) were analyzed.Results: Eighty-one stents were implanted in 61 CIA and 15 EIA lesions (41 with moderate/severe calcification). The mean lesion treated length was 29.3±13.9 mm. All devices were successfully deployed. MAE occurred in 3 (4.0%) of 75 subjects at 9 months. Primary patency and freedom from CD-TVR at 9 months were both 95.8%. ABI improved from 0.67±0.14 at baseline to 0.94±0.14 and 0.96±0.16 at 30 days and 9-month follow-up, respectively (p<0.001 for both). There were no differences with respect to any of the analyzed patient characteristics, including gender.Conclusion: Nine-month results of the VISIBILITY Iliac stent study ( ClinicalTrials.gov identifier NCT01402700) demonstrated safety and effectiveness for the treatment of atherosclerotic CIA and EIA lesions with the Visi-Pro stent across all treated cohorts. [ABSTRACT FROM AUTHOR]