Is It Always Unethical to Use a Placebo in a Clinical Trial?

Background to the debate: Placebos are used in trials to conceal whether a treatment is being given or not and hence to control for the psychosomatic effects of offering treatment. Placebo-controlled trials are controversial. Critics of such trials argue that if a proven effective therapy exists, a placebo should not be used. But proponents argue that placebo trials are still crucial to prove the efficacy and safety of many treatments

External Validation of Cardiovascular Risk Scores in the Southern Cone of Latin America: Which Predicts Better?

Introducción: La estimación inexacta del riesgo cardiovascular poblacional puede llevar a un manejo inadecuado de las intervenciones médicas preventivas, como, por ejemplo, el uso de estatinas. Objetivo: Evaluar la validez externa de ecuaciones de predicción de riesgo cardiovascular en población general del Cono Sur de Latinoamérica. Material y métodos: Se evaluaron ecuaciones que incluyen variables evaluadas en el estudio CESCAS y que predicen tanto morbilidad como mortalidad cardiovascular global (CUORE, Framingham, Globorisk y Pooled Cohort Studies Equations). Para cada ecuación se realizó un análisis independiente en el que se tuvieron en cuenta los eventos cardiovasculares relevados. Se evaluó la discriminación de cada ecuación a través del cálculo del estadístico-C y el índice Harrell C. Para evaluar la calibración se graficó la proporción de riesgos observados vs. estimados por quintilos de riesgo para cada ecuación y se calculó la pendiente β de regresión lineal para las estimaciones. Se calculó sensibilidad y especificidad para la detección de personas con elevado riesgo cardiovascular. Resultados: La mediana del tiempo de seguimiento de la cohorte al momento del análisis es de 2,2 años, con un rango intercuartilo de 1,9 a 2,8 años. Se incorporaron a los análisis 60 eventos cardiovasculares. Todos los valores de estadístico-C y del índice de Harrell fueron superiores a 0,7. El valor de la pendiente β más alejado de 1 fue el de Pooled Cohort Studies Euations. Conclusiones: Si bien los parámetros de validación externa evaluados fueron similares, CUORE, Globorisk y el índice de Framingham fueron las ecuaciones con mejores indicadores globales de predicción de riesgo cardiovascular.Background: Inaccurate estimates of demographic cardiovascular risk may lead to an inadequate management of preventive medical interventions such as the use of statins. Objectives: The aim of this study was to evaluate the external validity of cardiovascular risk equations in the general population of the Southern Cone of Latin America. Methods: Equations including variables evaluated in the CESCAS cohort study and that estimate overall cardiovascular mortality (CUORE, Framingham, Globorisk and Pooled Cohort Studies) were assessed. For each equation, an independent analysis was performed taking into account the cardiovascular events originally considered. Discrimination of each equation was evaluated through C-statistic and Harrell’s C-index. To assess calibration, a graph was built for each equation with the proportion of observed events vs. the proportion of estimated events by risk quintiles and the β slope of the resulting linear regression was calculated. Sensitivity and specificity were determined for the detection of people at high cardiovascular risk. Results: The median follow-up time of the cohort at the time of the analysis was 2.2 years, with an interquartile range of 1.9 to 2.8 years. Sixty cardiovascular events were incorporated into the analysis. All C-statistic and Harrell’s-C index values were greater than 0.7. The value of the β slope farthest from 1 was that of the Pooled Cohort Studies score. Conclusions: Although the external validation parameters evaluated were similar, CUORE, Globorisk and the Framingham equations showed the best global performance for cardiovascular risk estimation in our population.Fil: Gulayin, Pablo Elías. Universidad Nacional de La Plata; Argentina. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Danaei, Goodarz. Harvard University. Harvard School of Public Health; Estados UnidosFil: Gutierrez, Laura. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Poggio, Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: Ponzo, Jaqueline. Universidad de la República; UruguayFil: Lanas, Fernando. Universidad de La Frontera; ChileFil: Rubinstein, Adolfo Luis. Ministerio de Salud de la Nación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Irazola, Vilma. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentin

Documents from the May 23, 1984 meeting of the Associated Students of the University of Montana (ASUM)

Documents from the May 23, 1984 meeting of the Associated Students of the University of Montana (ASUM), including an agenda and meeting minutes

Stream fish populations in a watershed scale context for fish community dynamics in central Appalachian watersheds

In this study we first conducted a three pass removal study to estimate electrofishing capture probabilities for species and size classes of fish common in the Cheat River and Tygart River watersheds of West Virginia. We then calculated models of capture probabilities for 12 species that were divided into two size classes based on site-specific physico-chemical variables. We took these capture probability models and applied them to a watershed scale study in the Cheat River and Tygart Valley River watersheds of West Virginia. We sampled across the two watersheds with the objective of quantifying and relating juvenile and adult distributions within species along a stream size continuum. The 14 species that were included in the study we found to be mostly non-uniformly distributed across the watershed. We used general stream size to categorize where the concentrations of each species and size class were, in relation to the watershed and each other. Our analyses determined among species variations in the degree of overlap of juvenile and adult distributions within species. We generally related watershed population and community level organization to the within species juvenile and adult distributions

Стійка технологія переробки відходів електричного та електронного обладнання

Об’єкт досліджень: технологічні основи «переробки відходів електричного та електронного обладнання». Предмет досліджень: механізм піролізу, отримання рідкого палива, подрібнення друкованих плат після піролізу, вібраційний млин та його сили, які впливають на подрібнення. Вихідні дані для проведення роботи: характеристики друкованих плат та їх переробка у світі. Наукова новизна: відокремлення металевої фракції від наповнювачів, за рахунок ковкості металевої фракції при подрібнені та подальшому розділення при грохочені. Практична цінність: поліпшення екологічної складової за рахунок втілення нових технологій в сектор управління відходів та рециклінгу вже добутих мінералів. Дипломна робота написана англійською мовою та надалі буде захищена в ТУ "Фрайберзька гірнича академія"

Heat capacity and magnetoresistance in Dy(Co,Si)2 compounds

Magnetocaloric effect and magnetoresistance have been studied in Dy(Co1-xSix)2 [x=0, 0.075 and 0.15] compounds. Magnetocaloric effect has been calculated in terms of adiabatic temperatue change (Delta Tad) as well as isothermal magnetic entropy change (Delta SM) using the heat capacity data. The maximum values of DeltaSM and DeltaTad for DyCo2 are found to be 11.4 JKg-1K-1 and 5.4 K, respectively. Both DSM and DTad decrease with Si concentration, reaching a value of 5.4 JKg-1K-1 and 3 K, respectively for x=0.15. The maximum magnetoresistance is found to about 32% in DyCo2, which decreases with increase in Si. These variations are explained on the basis of itinerant electron metamagnetism occurring in these compounds.Comment: Total 8 pages of text and figure