Actualización del modelo de políticas en enfermedad cardiovascular en Argentina / Update of the cardiovascular disease policy model to predict cardiovascular events in Argentina

La enfermedad cardiovascular (ECV) es la principal causa de muerte en Argentina. Los modelos de simulació;n por computadora permiten extrapolar evidencia a poblaciones más amplias que las originalmente estudiadas, a lo largo de períodos prolongados, y comparar diferentes subpoblaciones. El Cardiovascular Disease Policy Model (CVDPM, por sus siglas en ingló;©s) es un modelo de simulació;n utilizado para representar y proyectar la mortalidad y morbilidad por ECV en la població;n de 35 o más aó;±os. El objetivo de este trabajo fue actualizar la versió;n argentina del CVDPM. Para esto, se utilizó; informació;n del Censo Nacional 2010, la Encuesta Nacional de Factores de Riesgo 2013, el estudio CESCAS I, y el estudio PrEViSTA, para actualizar la dinámica del tamaó;±o de la població;n, sus características demográficas, y la distribució;n de factores de riesgo cardiovasculares a lo largo del tiempo. Las proyecciones del modelo se calibraron comparándolas con informació;n sobre eventos de ECV y mortalidad en el aó;±o 2010 (aó;±o de referencia) en Argentina. Las estadísticas argentinas informaron que en 2010 la població;n de 35 o más aó;±os sufrió; un total de 41 219 infartos de miocardio (IM), 58 658 accidentes cerebrovasculares y 281 710 muertes totales. El CVDPM predijo 41 265 IM (diferencia: 0.11%), 58 584 accidentes cerebrovasculares (diferencia: 0.13%) y 280 707 muertes totales (diferencia: 0.36%). En todos los casos, la versió;n final del modelo predijo el nó;ºmero real de eventos cardiovasculares con una precisió;n superior al 99.5%, pudiendo ser utilizado para pronosticar cambios en la incidencia y mortalidad de ECV debidos de la implementació;n de políticas pó;ºblicas.

Cardiovascular disease (CVD) is the leading cause of death in Argentina. Computer simulation models allow to extrapolate evidence to broader populations than the originally studied, over longer timeframes, and to compare different subpopulations. The Cardiovascular Disease Policy Model (CVDPM) is a computer simulation state transition model used to represent and project future CVD mortality and morbidity in the population 35 years-old and older. The objective of this study was to update Argentina’s version of the CVDPM. For this purpose, information from the 2010 National Census, the 2013 National Risk Factor Survey, CESCAS I study, and PrEViSTA study were used to update the dynamics of population size, demographics, and CVD risk factor distributions over time. Model projections were later calibrated by comparing them to actual data on CVD events and mortality in the year 2010 (baseline year) in Argentina. Country statistics for people 35 years-old and older reported for 2010 a total of 41 219 myocardial infarctions (MIs), 58 658 strokes, and 281 710 total deaths. The CVDPM, in turn, predicted 41 265 MIs (difference: 0.11%), 58 584 strokes (difference: 0.13%), and 280 707 total deaths (difference: 0.36%) in the same population. In all cases, the final version of the model predicted the actual number of events with an accuracy superior to 99.5%, and could be used to forecast the changes in CVD incidence and mortality after the implementation of public policies.

Update of the cardiovascular disease policy model to predict cardiovascular events in Argentina

Cardiovascular disease (CVD) is the leading cause of death in Argentina. Computer simulation models allow to extrapolate evidence to broader populations than the originally studied, over longer timeframes, and to compare different subpopulations. The Cardiovascular Disease Policy Model (CVDPM) is a computer simulation state transition model used to represent and project future CVD mortality and morbidity in the population 35 years-old and older. The objective of this study was to update Argentina’s version of the CVDPM. For this purpose, information from the 2010 National Census, the 2013 National Risk Factor Survey, CESCAS I study, and PrEViSTA study were used to update the dynamics of population size, demographics, and CVD risk factor distributions over time. Model projections were later calibrated by comparing them to actual data on CVD events and mortality in the year 2010 (baseline year) in Argentina. Country statistics for people 35 years-old and older reported for 2010 a total of 41 219 myocardial infarctions (MIs), 58 658 strokes, and 281 710 total deaths. The CVDPM, in turn, predicted 41 265 MIs (difference: 0.11%), 58 584 strokes (difference: 0.13%), and 280 707 total deaths (difference: 0.36%) in the same population. In all cases, the final version of the model predicted the actual number of events with an accuracy superior to 99.5%, and could be used to forecast the changes in CVD incidence and mortality after the implementation of public policies.

La enfermedad cardiovascular (ECV) es la principal causa de muerte en Argentina. Los modelos de simulació;n por computadora permiten extrapolar evidencia a poblaciones más amplias que las originalmente estudiadas, a lo largo de períodos prolongados, y comparar diferentes subpoblaciones. El Cardiovascular Disease Policy Model (CVDPM, por sus siglas en ingló;©s) es un modelo de simulació;n utilizado para representar y proyectar la mortalidad y morbilidad por ECV en la població;n de 35 o más aó;±os. El objetivo de este trabajo fue actualizar la versió;n argentina del CVDPM. Para esto, se utilizó; informació;n del Censo Nacional 2010, la Encuesta Nacional de Factores de Riesgo 2013, el estudio CESCAS I, y el estudio PrEViSTA, para actualizar la dinámica del tamaó;±o de la població;n, sus características demográficas, y la distribució;n de factores de riesgo cardiovasculares a lo largo del tiempo. Las proyecciones del modelo se calibraron comparándolas con informació;n sobre eventos de ECV y mortalidad en el aó;±o 2010 (aó;±o de referencia) en Argentina. Las estadísticas argentinas informaron que en 2010 la població;n de 35 o más aó;±os sufrió; un total de 41 219 infartos de miocardio (IM), 58 658 accidentes cerebrovasculares y 281 710 muertes totales. El CVDPM predijo 41 265 IM (diferencia: 0.11%), 58 584 accidentes cerebrovasculares (diferencia: 0.13%) y 280 707 muertes totales (diferencia: 0.36%). En todos los casos, la versió;n final del modelo predijo el nó;ºmero real de eventos cardiovasculares con una precisió;n superior al 99.5%, pudiendo ser utilizado para pronosticar cambios en la incidencia y mortalidad de ECV debidos de la implementació;n de políticas pó;ºblicas.

¿Es ética la utilización de técnicas de simulación en la docencia médica de pregrado? Reflexión bioética / Is ethical to use simulation techniques in undergraduate medical teaching?

The use of simulation models in undergraduate medical teaching is now a reality in Chile. This technology provides scenarios of different complexities, and it has a number of advantages for patients' security as well as comfort. The main benefits, limitations and risks of these simulation techniques are pointed out in this article. It is concluded that its use in teaching medical students is not only ethical, but also an indispensable complement in medical education.

La utilización de modelos de simulación en la docencia de pregrado en medicina ya es una realidad en nuestro país. Pone al alcance del estudiante diversos escenarios de la atención médica, a distintos niveles de complejidad. Tiene muchas ventajas y evita molestias e incomodidades a los pacientes reales. Se proponen sus principales ventajas y riesgos y se concluye que no sólo es ética su utilización, sino que además es un complemento docente indispensable.

Regression and simulation models for human and baboon brain parameters / Modelo regresivo y simulación para los parámetros cerebrales humanos y del babuino

The variations in morphometric parameter of mammalian brains may be influenced by process of functional complexity, evolution and adaptation. Comparative analysis of linear measurements of cerebrum in the human and baboon has shown morphometric differences. In the present study linear measurements from human and baboon cerebrum (n=10 each) were used to predict various values for human and baboon brain and body parameters through multiple regression models. The average brain weights were found to be 2.08 percent and 0.84 percent of the body weights for humans and baboons respectively. The elasticity of regression models revealed that unit percentage increase in Occipital-Frontal (OF) distance would increase the human brain weight by 66.19 percent, while the baboon brain weight would increase by 7.63 percent. The unit percentage increase in the Height of Temporal Lobe (HTL) would increase the human brain weight by 16.28 percent, while the baboon brain weight would increase by only 0.28 percent. Unit percentage increase in Frontal-Temporal (FT) distance would decrease the human and baboon brain weights by 14.04 percent and 0.46 percent respectively. Inter-species values were also predicted through simulation techniques by using the ratios of model parameters with application of programming language Python. The OF, FT and HTL values for human were found to be 2.01 times, 1.55 times and 1.91 times respectively to that of baboon.

Las variaciones en los parámetros morfométricos del cerebro de los mamíferos pueden estar influenciadas por el proceso de complejidad funcional de la evolución y adaptación. Análisis comparativo de las mediciones lineales del cerebro en el humano y babuino han puesto de manifiesto las diferencias morfométricas. En este estudio las mediciones lineales del cerebro humano y babuinos (n = 10 cada uno) fueron utilizados para predecir los valores distintivos para el cerebro de humanos y monos babuinos y los parámetros del cuerpo a través de modelos de regresión múltiple. El peso medio del cerebro resultó ser 2,08 por ciento y 0,84 por ciento del peso corporal de los seres humanos y los babuinos, respectivamente. La elasticidad de los modelos de regresión reveló que el aumento de una unidad porcentual en la distancia occipital-frontal (DE) aumentaría el peso del cerebro humano en 66,19 por ciento, mientras que el peso del cerebro babuino se incrementaría en 7,63 por ciento. El porcentaje de aumento en la altura de lóbulo temporal (HTL) aumentaría el peso del cerebro humano en 16,28 por ciento, mientras que el peso del cerebro babuino aumentaría en sólo el 0,28 por ciento. Si aumenta la distancia frontal-temporal (FT) se reduciría el peso del cerebro humano y babuinos en 14,04 por ciento y 0,46 por ciento, respectivamente. También se prevéen valores entre las especies a través de técnicas de simulación, mediante el uso de proporciones de los parámetros del modelo con la aplicación del lenguaje de programación Python. Los valores humanos de DE, FT y HTL resultaron ser 2,01, 1,55 y 1,91 veces, respectivamente con respecto a la de los babuinos.

Avaliação de modelos para predição da energia metabolizável do milho para aves / Evaluation of models to predict metabolizable energy of corn for chickens

O estudo foi realizado com o objetivo de avaliar modelos de predição do valor de energia metabolizável aparente corrigida (EMAn) do milho para aves. Foi organizado um banco de dados contendo informações de experimentos, publicados na literatura nacional entre os anos de 1994 a 2007. Foram utilizados dados de composição química, valores de energia bruta e EMAn de 97 amostras de milho, provenientes de estudos em que os valores de EMAn foram determinados pelo método tradicional de coleta total de excretas com pintos de linhagem de corte. Avaliaram-se cinco modelos, sendo quatro deles sugeridos para estimar a EMAn do milho e um para estimar EMAn de alimentos energéticos. Os modelos estudados foram: EMAnC1 = 36,21*PB + 85,37*EE + 37,26*ENN; EMAnC2 = 37,50*PB + 85,37*EE + 38,21*ENN; EMAnC3 = 4021,8 - 227,5*MM; EMAnC4 = 4337,27 - 57,17*FDN; e EMAnC5 = 4371,18 - 26,48*PB + 30,65*EE - 126,93*MM - 52,26*FB - 25,14*FDN + 24,40*FDA. Os valores de EMAn estimados pelos modelos foram comparados com os valores observados utilizando-se a análise de regressão. Em todos os modelos avaliados, houve rejeição (P<0,001) da hipótese de nulidade, demonstrando diferenças entre os valores de EMAn observados e calculados. No desdobramento do quadrado médio do erro de predição (MSD) em seus componentes, constatou-se que os dados simulados pelos modelos EMAnC1, EMAnC3 e EMAnC5 apresentam desvios de magnitude e padrão de flutuação em relação aos dados observados. Por outro lado, verificou-se que as estimativas realizadas com os modelos EMAnC2 e EMAnC4 tiveram predomínio do componente que expressa o vício de predição, indicando o viés constante observado na relação entre os valores observados e preditos. Concluiu-se que nenhum dos cinco modelos estudados permitiu estimar com precisão e acurácia os valores de energia metabolizável aparente corrigida do milho para aves.

A study was realized to validate models to predict apparent metabolizable energy (AMEn) of corn used in chickens diets. Data set with informations of experiments published in national literature among 1994 to 2007 was organized. Chemical composition, gross energy and AMEn of 97 corn samples were including in data set. Studies which AMEn was determined by the traditional method of excreta collection with growing chickens were selected. Five models were evaluates, being four recommended for application in corn and one for application in energetic feedstuffs. The models studied were AMEnC1=36.21*CP + 85.37*EE + 37.26*NNE; AMEnC2 =37.5*CP + 85.37*EE + 38.21*NNE; AMEnC3 =4021.8 - 227.5*ASH; AMEnC4 =4337.27 - 57.17*NDF; e AMEnC5 =4371.18 - 26.48*CP + 30.65*EE - 126.93*ASH - 52.26*CF - 25.14*NDF + 24.40*ADF. The values of AMEn obtained for the models were compared with the observed values using regression analysis. In all the evaluated models there is rejection of the nullity hypothesis, showing differences between estimated and calculated AMEn values. Decomposition of mean squared deviation (MSD) has been demonstrated that calculated values from models AMEnC1, AMEnC3 and AMEnC5 showed that its models failed to simulate the magnitude and pattern of fluctuation. On the other hand, the estimates made with models AMEnC2 e AMEnC4 showed predominance of component bias of prediction that indicates the models failed to simulate the variability of the data around the mean. Energy values predicted using differents models were compared with calculated values by regression analysis. In conclusion any of five models studied allow estimating precisely the apparent metabolizable energy of corn to chickens.

Desempenho de bovinos simulado pelo modelo Pampa Corte e obtido por experimentação / Animal performance simulated by Pampa Corte model with experimental records

Este trabalho tem como objetivo verificar a confiabilidade do Modelo Pampa Corte na predição de desempenho de bovinos de corte, em sistemas de pastejo. Para tanto, foram confrontados os valores preditos pelo modelo com dados disponíveis na literatura. Foram verificados coeficientes de correlação acima de 90 por cento entre os dados reais e os simulados em todas as alternativas testadas. O banco de dados do Modelo precisa ser ampliado em termos de alternativas de produtividade das forrageiras, em diferentes condições climáticas. Os parâmetros qualitativos degradabilidade da proteína bruta e fibra em detergente neutro da consorciação aveia preta e azevém necessitam ainda ser pesquisados, assim como o desempenho de animais em pastagens singulares de aveia ou azevém.

This study had the objective to evaluate Pampa Corte Model’s reliability in predicting beef cattle performance in grazing systems. For this purpose, model’s predicted values were compared to available data base of published papers. Correlation coefficients above 90 percent were obtained between simulated and real data in all tested alternatives. Model’s data base should be enlarged by forage productivity data in different climatic conditions. Mixtures of Italian ryegrass and oat need more studies to obtain qualitative parameters (crude protein degradability and neutral detergent fiber), as well, animal performance in the single pastures of oat or Italian ryegrass.