Robust Minimum Divergence Estimation for the Multinomial Circular Logistic Regression Model.

Circular data are extremely important in many different contexts of natural and social science, from forestry to sociology, among many others. Since the usual inference procedures based on the maximum likelihood principle are known to be extremely non-robust in the presence of possible data contamination, in this paper, we develop robust estimators for the general class of multinomial circular logistic regression models involving multiple circular covariates. Particularly, we extend the popular density-power-divergence-based estimation approach for this particular set-up and study the asymptotic properties of the resulting estimators. The robustness of the proposed estimators is illustrated through extensive simulation studies and few important real data examples from forest science and meteorology.

Model Selection in a Composite Likelihood Framework Based on Density Power Divergence.

This paper presents a model selection criterion in a composite likelihood framework based on density power divergence measures and in the composite minimum density power divergence estimators, which depends on an tuning parameter α . After introducing such a criterion, some asymptotic properties are established. We present a simulation study and two numerical examples in order to point out the robustness properties of the introduced model selection criterion.

New robust statistical procedures for the polytomous logistic regression models.

This article derives a new family of estimators, namely the minimum density power divergence estimators, as a robust generalization of the maximum likelihood estimator for the polytomous logistic regression model. Based on these estimators, a family of Wald-type test statistics for linear hypotheses is introduced. Robustness properties of both the proposed estimators and the test statistics are theoretically studied through the classical influence function analysis. Appropriate real life examples are presented to justify the requirement of suitable robust statistical procedures in place of the likelihood based inference for the polytomous logistic regression model. The validity of the theoretical results established in the article are further confirmed empirically through suitable simulation studies. Finally, an approach for the data-driven selection of the robustness tuning parameter is proposed with empirical justifications.

Composite Likelihood Methods Based on Minimum Density Power Divergence Estimator.

In this paper, a robust version of the Wald test statistic for composite likelihood is considered by using the composite minimum density power divergence estimator instead of the composite maximum likelihood estimator. This new family of test statistics will be called Wald-type test statistics. The problem of testing a simple and a composite null hypothesis is considered, and the robustness is studied on the basis of a simulation study. The composite minimum density power divergence estimator is also introduced, and its asymptotic properties are studied.

Uso de la escala CHADS 2 como predictor de riesgo de mortalidad en pacientes hipertensos. El estudio FAPRES / Use of the CHADS 2 score as a predictor of the risk of mortality in hypertensive patients. The FAPRES study

Fundamentos y objetivo: El objetivo del estudio es analizar la escala CHADS2 como marcador de riesgo de mortalidad en pacientes hipertensos, independientemente de la presencia o no de fibrilación auricular. Métodos: Se incluyó a 1.003 pacientes hipertensos ≥ 65 años, recogiendo factores de riesgo y puntuación CHADS2. Se realizó un seguimiento clínico de la mortalidad. Resultados: La media de edad de la población fue 72,8 ± 5,8 años; el 47,5% eran varones. Durante el seguimiento hubo 41 muertes, 20 de origen cardiovascular. Los pacientes con mayor CHADS2 tuvieron una mayor mortalidad: 1,5% en CHADS2 = 1; 4,7% en CHADS2 = 2; 9,1% en CHADS2 = 3, y 7,8% en CHADS2 ≥ 4. Conclusiones: La puntuación CHADS2 puede ser un instrumento clínico de sencilla aplicación para identificar pacientes hipertensos con alto riesgo de mortalidad (AU)

Foundations and aim: The aim of this study is to analyze the CHADS2 score as a marker of the risk of mortality in hypertensive patients, with and without the presence of atrial fibrillation. Methods: We included 1,003 hypertensive patients ≥ 65 years. Risk factors, and CHADS2 score were recorded among other factors, as well as clinical follow-up of number and type of deaths. Results: Mean age was 72.8 ± 5.8 years, and 47.5% were men. During follow-up there were 41 deaths, 20 were of cardiovascular origin. Patients with higher CHADS2 had a higher mortality: 1.5% CHADS2 = 1; 4.7% in CHADS2 = 2; 9.1% in CHADS2 = 3, and 7.8% in CHADS2 ≥ 4. Conclusions: The CHADS2 score can be a clinical instrument of easy application to identify hypertensive patients with a high risk of mortality (AU)

[Use of the CHADS2 score as a predictor of the risk of mortality in hypertensive patients. The FAPRES study]. / Uso de la escala CHADS2 como predictor de riesgo de mortalidad en pacientes hipertensos. El estudio FAPRES.

FOUNDATIONS AND AIM: The aim of this study is to analyze the CHADS2 score as a marker of the risk of mortality in hypertensive patients, with and without the presence of atrial fibrillation. METHODS: We included 1,003 hypertensive patients≥65 years. Risk factors, and CHADS2 score were recorded among other factors, as well as clinical follow-up of number and type of deaths. RESULTS: Mean age was 72.8±5.8 years, and 47.5% were men. During follow-up there were 41 deaths, 20 were of cardiovascular origin. Patients with higher CHADS2 had a higher mortality: 1.5% CHADS2=1; 4.7% in CHADS2=2; 9.1% in CHADS2=3, and 7.8% in CHADS2≥4. CONCLUSIONS: The CHADS2 score can be a clinical instrument of easy application to identify hypertensive patients with a high risk of mortality.

Seudoacalasia en paciente con antecedentes de linfoma no Hodgkin / Pseudoachalasia in a patient with a history of non-Hodgkin lymphoma

No disponible

La puntuación CHADS2 como predictor de riesgo de ictus en ausencia de fibrilación auricular en pacientes hipertensos de 65 o más años / The CHADS2 score to predict stroke risk in the absence of atrial fibrillation in hypertensive patients aged 65 years or older

Introducción y objetivos: La puntuación CHADS2 es una demostrada herramienta fundamental para identificar el riesgo cardioembólico, fundamentalmente el ictus, de pacientes con fibrilación auricular no valvular, con el propósito de indicar la terapia anticoagulante. El objetivo del presente estudio es analizar la utilidad de dicha puntuación para pacientes hipertensos sin fibrilación auricular conocida en una zona mediterránea. Métodos: Se incluyó a 887 pacientes hipertensos de edad ≥ 65 años, no anticoagulados y sin fibrilación auricular, que acudieron a la consulta médica. Se recogieron los principales factores de riesgo, la historia cardiovascular, el tratamiento farmacológico, una analítica básica y un electrocardiograma y se calculó la puntuación CHADS2 (insuficiencia cardiaca, hipertensión, edad ≥ 75 años, diabetes mellitus e ictus previo o accidente isquémico transitorio). Se realizó un seguimiento clínico con recogida de los ingresos hospitalarios por ictus o accidente isquémico transitorio. La mediana del seguimiento fue 804 días. Resultados: La media de edad era 72,5 ± 5,7 años, con el 46,6% de varones, el 27,8% de diabéticos y el 8,6% de fumadores. Durante el seguimiento, 40 pacientes fueron ingresados por ictus o accidente isquémico transitorio (4,5%). El análisis de supervivencia libre de eventos mostró diferencias significativas en función de la puntuación CHADS2 (log rank test, p < 0,001). En el análisis multivariable, el tabaquismo y un CHADS2 ≥ 3 fueron predictores independientes de ictus o accidente isquémico transitorio. Conclusiones: La puntuación CHADS2 puede ser una herramienta útil para identificar el riesgo de ictus o accidente isquémico transitorio de los pacientes hipertensos sin fibrilación auricular conocida (AU)

Introduction and objectives: The CHADS2 score is a proven, essential tool for estimating cardioembolic risk (mainly stroke) in patients with nonvalvular atrial fibrillation, with the purpose of determining the indication for anticoagulant therapy. In this study we analyzed the use of CHADS2 in hypertensive patients without known atrial fibrillation in a Mediterranean population. Methods: The study included 887 hypertensive patients aged 65 years or older without atrial fibrillation or anticoagulant therapy, who attended a medical consultation. Data on the patients’ main risk factors, cardiovascular history, and medication were collected, basic laboratory analyses and electrocardiography were performed, and the CHADS2 score (heart failure, hypertension, age ≥ 75 years, diabetes mellitus, and previous stroke or transient ischemic attack) was calculated. A clinical follow-up was carried out, recording hospital admissions for a stroke or transient ischemic attack. The median duration of follow-up was 804 days. Results: Mean age was 72.5 (SD,5.7) years, 46.6% were men, 27.8% had diabetes, and 8.6% were smokers. During follow-up, 40 patients were hospitalized for a stroke or transient ischemic attack (4.5%). The event-free survival analysis showed significant differences according to the CHADS2 score (log rank test, P < .001). On multivariate analysis, smoking and CHADS2 ≥3 were independent predictors of stroke or transient ischemic attack. Conclusions: The CHADS2 may be useful for estimating the risk of stroke or transient ischemic attack in hypertensive patients without known atrial fibrillation (AU)

The CHADS2 Score to Predict Stroke Risk in the Absence of Atrial Fibrillation in Hypertensive Patients Aged 65 Years or Older.

INTRODUCTION AND OBJECTIVES: The CHADS2 score is a proven, essential tool for estimating cardioembolic risk (mainly stroke) in patients with nonvalvular atrial fibrillation, with the purpose of determining the indication for anticoagulant therapy. In this study we analyzed the use of CHADS2 in hypertensive patients without known atrial fibrillation in a Mediterranean population. METHODS: The study included 887 hypertensive patients aged 65 years or older without atrial fibrillation or anticoagulant therapy, who attended a medical consultation. Data on the patients' main risk factors, cardiovascular history, and medication were collected, basic laboratory analyses and electrocardiography were performed, and the CHADS2 score (heart failure, hypertension, age ≥ 75 years, diabetes mellitus, and previous stroke or transient ischemic attack) was calculated. A clinical follow-up was carried out, recording hospital admissions for a stroke or transient ischemic attack. The median duration of follow-up was 804 days. RESULTS: Mean age was 72.5 (SD,5.7) years, 46.6% were men, 27.8% had diabetes, and 8.6% were smokers. During follow-up, 40 patients were hospitalized for a stroke or transient ischemic attack (4.5%). The event-free survival analysis showed significant differences according to the CHADS2 score (log rank test, P < .001). On multivariate analysis, smoking and CHADS2 ≥3 were independent predictors of stroke or transient ischemic attack. CONCLUSIONS: The CHADS2 may be useful for estimating the risk of stroke or transient ischemic attack in hypertensive patients without known atrial fibrillation.

Left ventricular pseudoaneurysm found after mitral valve replacement performed 30 years earlier.

Pseudoaneurysm of the left ventricle (LV) is a rare cardiac disease that occurs after myocardial infarction or cardiac surgery. Because patients frequently present with nonspecific symptoms, a high index of suspicion is needed to make the diagnosis. This report describes an unusual case demonstrating a large LV pseudoaneurysm after mitral valve replacement performed 30 years earlier.