نتایج جستجو برای: correlated frailty

تعداد نتایج: 262654  

ژورنال: اندیشه آماری 2021

Many populations encountered in survival analysis are often not homogeneous. Individuals are flexible in their susceptibility to causes of death, response to treatment and influence of various risk factors. Ignoring this heterogeneity can result in misleading conclusions. To deal with these problems, the proportional hazard frailty model was introduced. In this paper, the frailty model is ex...

Journal: :Lifetime data analysis 2010
M A Jonker D I Boomsma

Family survival data can be used to estimate the degree of genetic and environmental contributions to the age at onset of a disease or of a specific event in life. The data can be modeled with a correlated frailty model in which the frailty variable accounts for the degree of kinship within the family. The heritability (degree of heredity) of the age at a specific event in life (or the onset of...

2016
Kate J. Gregorevic Ruth E. Hubbard Wen K. Lim Benny Katz

BACKGROUND Increasing frailty is associated with risk of mortality and functional decline in hospitalized older adults, but there is no consensus on the best screening method for use by non-geriatricians. The objective of this study is to determine whether the clinical frailty scale (CFS) can be used to identify patient baseline frailty status in the acute general medical setting when used by j...

2017
Martin Ritt Jakob Jäger Julia Isabel Ritt Cornel Christian Sieber Karl-Günter Gaßmann

BACKGROUND Uncomplicated frailty instruments are desirable for use in a busy clinical setting. The aim of this study was to operationalize a frailty index (FI) from routine blood and urine tests, and to evaluate the properties of this FI compared to other frailty instruments. MATERIALS AND METHODS We conducted a secondary analysis of a prospective cohort study on 306 patients aged ≥65 years h...

Journal: :Age and ageing 2005
Kenneth Rockwood

At present, frailty is defined variably. Some consensus on a definition is likely to emerge, but the basis for a successful definition needs to be explored. Here, a classic approach to validation is proposed: a successful definition of frailty should be multifactorial but must also manage the many factors in a way that takes their interactions into account. It is likely to be correlated with di...

Journal: :Journal of the American Geriatrics Society 2005
Arnold Mitnitski Xiaowei Song Ingmar Skoog G A Broe Jafna L Cox Eva Grunfeld Kenneth Rockwood

OBJECTIVES To investigate the relationship between accumulated health-related problems (deficits), which define a frailty index in older adults, and mortality in population-based and clinical/institutional-based samples. DESIGN Cross-sectional and cohort studies. SETTING Seven population-based and four clinical/institutional surveys in four developed countries. PARTICIPANTS Thirty-six tho...

2005
Anatoli I. Yashin Ivan A. Iachine Alexander Z. Begun James W. Vaupel

Hidden differences in the survival chances of individuals in a population influence the shape of the mortality rate observed in demographic and epidemiological studies. To evaluate the contribution of such hidden variations to observed hazards, frailty models have been suggested. The application of these models to the analysis of survival data in demography, epidemiology, and biostatistics has ...

Hassan Rezaeipandari, Hossein Matlabi, Mirdavoud Mousavisisi, Seyed Morteza Shamshirgaran,

Introduction: Frailty is a common geriatric syndrome. Studies of frailty and old age have been able to help reduce its underlying causes and complication. Understanding the frailty and its associated factors in developing countries such as Iran, can help gather information on conditions of the elderly and better plan for this age population. Therefore, the present study was implemented to inves...

2018
Steven Abrams Andreas Wienke Niel Hens

Frailty models are often used in survival analysis to model multivariate time-to-event data. In infectious disease epidemiology, frailty models have been proposed to model heterogeneity in the acquisition of infection and to accommodate association in the occurrence of multiple types of infection. Although traditional frailty models rely on the assumption of lifelong immunity after recovery, re...

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