Journal ArticleDOI
Frailty models for survival data
TLDR
A frailty model is a random effects model for time variables, where the random effect (the frailty) has a multiplicative effect on the hazard.Abstract:
A frailty model is a random effects model for time variables, where the random effect (the frailty) has a multiplicative effect on the hazard. It can be used for univariate (independent) failure times, i.e. to describe the influence of unobserved covariates in a proportional hazards model. More interesting, however, is to consider multivariate (dependent) failure times generated as conditionally independent times given the frailty. This approach can be used both for survival times for individuals, like twins or family members, and for repeated events for the same individual. The standard assumption is to use a gamma distribution for the frailty, but this is a restriction that implies that the dependence is most important for late events. More generally, the distribution can be stable, inverse Gaussian, or follow a power variance function exponential family. Theoretically, large differences are seen between the choices. In practice, using the largest model makes it possible to allow for more general dependence structures, without making the formulas too complicated.read more
Citations
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Journal ArticleDOI
Anatomical and clinical characteristics to guide decision making between coronary artery bypass surgery and percutaneous coronary intervention for individual patients: development and validation of SYNTAX score II
Vasim Farooq,David van Klaveren,Ewout W. Steyerberg,Emanuele Meliga,Yvonne Vergouwe,Alaide Chieffo,Arie Pieter Kappetein,Antonio Colombo,David R. Holmes,Michael J. Mack,Ted Feldman,Marie Claude Morice,Elisabeth Ståhle,Yoshinobu Onuma,Marie Angèle Morel,Hector M. Garcia-Garcia,Gerrit Anne van Es,Keith D. Dawkins,Friedrich W. Mohr,Patrick W. Serruys +19 more
TL;DR: Long-term (4-year) mortality in patients with complex coronary artery disease can be well predicted by a combination of anatomical and clinical factors in SYNTAX score II, which can better guide decision making between CABG and PCI than the original anatomical SYN TAX score.
Book ChapterDOI
Models, definitions, and criteria of frailty.
TL;DR: This chapter will examine the current state of research on frailty, with a working definition of frailty described and a number of competing and complementary models for its development described.
Journal ArticleDOI
Comparative outcome of reduced intensity and myeloablative conditioning regimen in HLA identical sibling allogeneic haematopoietic stem cell transplantation for patients older than 50 years of age with acute myeloblastic leukaemia: a retrospective survey from the Acute Leukemia Working Party (ALWP) of the European group for Blood and Marrow Transplantation (EBMT).
M. Aoudjhane,Myriam Labopin,Norbert-Claude Gorin,A. Shimoni,T. Ruutu,H.-J. Kolb,Francesco Frassoni,J. M. Boiron,J. L. Yin,Jürgen Finke,H. Shouten,D. Blaise,M. Falda,A. A. Fauser,Jordi Esteve,Emmanuelle Polge,S. Slavin,D. Niederwieser,Arnon Nagler,Vanderson Rocha +19 more
TL;DR: Results of reduced intensity conditioning regimen (RIC) in the HLA identical haematopoietic stem cell transplantation (HSCT) setting have not been compared to those after myeloablative regimen HSCT in patients with acute myeloblastic leukaemia over 50 years of age, and these results may set the grounds for prospective trials comparing RIC with other strategies of treatment in elderly AML.
Journal ArticleDOI
Parametric frailty and shared frailty survival models
TL;DR: In this article, the authors compare parametric and shared frailty models in Stata via the streg command, and show that the parametric models are equivalent in certain situations.
Journal ArticleDOI
Estimation of multivariate frailty models using penalized partial likelihood.
TL;DR: This work proposes a model based on multiplicative frailties with a multivariate log-normal joint distribution with a generalization of the one presented by McGilchrist (1993, Biometrics 49, 221-225) based on Laplace approximation of the likelihood function.
References
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TL;DR: The drum mallets disclosed in this article are adjustable, by the percussion player, as to balance, overall weight, head characteristics and tone production of the mallet, whereby the adjustment can be readily obtained.
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Journal ArticleDOI
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