Search results for "Proportion"
showing 10 items of 877 documents
Comment on ‘Generating survival times to simulate Cox proportional hazards models with time-varying covariates’
2013
IndElec: A Software for Analyzing Party Systems and Electoral Systems
2011
IndElec is a software addressed to compute a wide range of indices from electoral data, which are intended to analyze both party systems and electoral systems in political studies. Further, IndElec can calculate such indices from electoral data at several levels of aggregation, even when the acronyms of some political parties change across districts. As the amount of information provided by IndElec may be considerable, this software also aids the user in the analysis of electoral data through three capabilities. First, IndElec automatically elaborates preliminary descriptive statistical reports of computed indices. Second, IndElec saves the computed information into text files in data matri…
Segmented relationships to model erosion of regression effect in Cox regression
2010
In this article we propose a parsimonious parameterisation to model the so-called erosion of the covariate effect in the Cox model, namely a covariate effect approaching to zero as the follow-up time increases. The proposed parameterisation is based on the segmented relationship where proper constraints are set to accomodate for the erosion. Relevant hypothesis testing is discussed. The approach is illustrated on two historical datasets in the survival analysis literature, and some simulation studies are presented to show how the proposed framework leads to a test for a global effect with good power as compared with alternative procedures. Finally, possible generalisations are also present…
A comparison of semiparametric approaches to evaluate composite endpoints in heart failure trials
2021
In heart failure trials efficacy is usually proven by a composite endpoint including cardiovascular death (CVD) and recurrent heart failure hospitalisations (HFH), evaluated with time-to-first-event analysis based on a Cox model. As a considerable fraction of events is ignored that way, recurrent event[for full text, please go to the a.m. URL]
Flexible latent trait aggregation to analyze employability after the Ph.D. in Italy
2015
The analysis of satisfaction, employability and economic perspectives after the Ph.D. in Italy has not received adequate attention in the past, especially in terms of comparison among universities. To analyze these aspects, in this paper we consider data from the survey ‘Statistica in TEma di Laureati e LAvoro’ on doctors who achieved the title on 2007, 2008 and 2009 [CILEA, Laureati STELLA, indagine occupazionale post-dottorato, dottori di ricerca 2007–2008, Tech. Rep., CILEA, Segrate, 2010; CILEA,Laureati STELLA, indagine occupazionale post-dottorato, dottori di ricerca 2008–2009, Tech. Rep., CILEA, Segrate, 2011]. To deal with the complex, multidimensional nature of the concept, we propo…
Electrochemical and DFT studies of the oxidative decomposition of the trihydride complexes Cp*M(dppe)H3 (M = Mo, W) in acetonitrile
2006
International audience; A detailed electrochemical study of the oxidative decomposition of the trihydride complexes Cp*M(dppe)H3 (M = Mo, W) in acetonitrile is presented. For the Mo complex, the decomposition occurs by four different pathways involving classical and non-classical tautomers, whereas only the classical form is accessible for the W derivative. Each of the decomposition pathways has been quantitatively assessed by analyses of the linear sweep voltammograms. In addition to the previously established (B. Pleune, D. Morales, R. Meunier-Prest, P. Richard, E. Collange, J. C. Fettinger and R. Poli, J. Am. Chem. Soc., 1999, 121, 2209–2225) deprotonation, disproportionation, and H2 red…
Comparison of Prognostic Signatures in Node-Negative Tamoxifen-Treated Breast Cancer Patients.
2009
Abstract Background: A number of molecular signatures have been published to aid breast cancer prognosis and therapy response prediction. A 76-gene signature has been developed in a node-negative patient cohort that did not receive systemic therapy.1 Another prognostic 97-gene signature measures predominantly proliferation-associated genes.2 Finally, a 21-gene signature has been developed for node-negative and estrogen receptor–positive breast cancer patients treated with tamoxifen in the adjuvant setting.3 Here we compare the prognostic performance of all three published algorithms in a cohort of 189 node-negative breast cancer patients treated with tamoxifen.Materials and Methods: Fresh-f…
Les méthodes biproportionnelles, un outil de reconstitution ou de comparaison de tableaux de contingence
2020
Un tableau de nombres dont on connaît le total de ses colonnes et lignes (ou « marges ») est appelé « tableau de contingence ». Un tel tableau se rencontre quand on étudie les échanges entre pays ou régions, les flux migratoires ou financiers, etc. Le premier problème qu’on étudie est la reconstitution du tableau quand on ne connaît que ses marges, mais pas les données du tableau elles-mêmes, sachant que celles-ci sont néanmoins proches de celles d’un autre tableau. C’est le cas par exemple quand on veut prévoir l’origine des échanges entre pays en connaissant seulement le total de ce qu’ils vont exporter et importer. Le deuxième problème étudié est l’évaluation de ce qui a changé entre deu…
Joint associations of accelerometer-measured physical activity and sedentary time with all-cause mortality: a harmonised meta-analysis in more than 4…
2020
Funder: National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care East Midlands
Patients' sex and emotional support as predictors of death and clinical deterioration in the Waiting for a New Heart Study: results from the 1-year f…
2011
Context—Little is known about the role of patient's sex and emotional support in the prognosis of heart transplant candidates.Objective—To examine patient's sex and emotional support as predictors of outcomes in the Waiting for a New Heart Study.Design, Setting, and Participants—The Waiting for a New Heart Study is a prospective observational study of 318 patients (18% female) newly added to the waiting list for a heart transplant. Demographic, medical, psychosocial characteristics (including social support [ENRICHD Social Support Index; high vs low support]) were assessed at the time of wait-listing.Main Outcomes—Time until death/delisting due to deteriorated health, considering competing …