BACKGROUND Readmissions after hospital discharge are common and costly, but prediction models are poor at identifying patients at high risk of readmission. We evaluated the impact of frailty on readmission or death within 30 days after discharge from general internal medicine wards. METHODS We prospectively enrolled patients discharged from 7 medical wards at 2 teaching hospitals in Edmonton....

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...

The concept of frailty has been evolving dramatically for the past 30 years. Through its evolution, a variety of single and multidimensional models have been used to describe frailty. This article reviews the current literature related to the defining dimensions of frailty and identifies the gaps in the literature requiring additional research. A detailed literature review was performed to iden...

Due to natural or artificial clustering, multivariate survival data often arise in biomedical studies, for example, a dental study involving multiple teeth from each subject. A certain proportion of subjects in the population who are not expected to experience the event of interest are considered to be "cured" or insusceptible. To model correlated or clustered failure time data incorporating a ...

The impact of antiretroviral therapy (ART) on frailty among human immunodeficiency virus (HIV)-infected adults has not been well described. HIV-infected participants aged ≥40 years with initial ART receipt through a randomized, controlled AIDS Clinical Trials Group trial completed a frailty assessment. Ordinal logistic regression models examined factors associated with frailty. Of 1016 particip...

Dependence Measures in Bivariate Gamma Frailty Models Bivariate duration data frequently arise in economics, biostatistics and other areas. In “bivariate frailty models”, dependence between the frailties (i.e., unobserved determinants) induces dependence between the durations. Using notions of quadrant dependence, we study restrictions that this imposes on the implied dependence of the duration...

Assessing agreement is often of interest in biomedical sciences to evaluate the similarity of measurements produced by different raters or methods on the same subjects. We investigate the agreement structure between bivariate survival times for a class of frailty models. Conditional on the frailty, bivariate survival times are assumed to be independent and follow a Weibull distribution. We pres...

Frailty, a clinical syndrome that typically occurs in older adults, implies a reduced ability to tolerate biological stressors. Frailty accompanies many age-related diseases but can also occur without overt evidence of end-organ disease. The condition is associated with circulating inflammatory cytokines and sarcopenia, features that are shared with heart failure (HF). However, the biological u...

BACKGROUND The relationship between frailty and gait characteristics other than velocity has received little attention. Gait variability quantifies the automaticity of gait with greater variability usually indicating an irregular and unstable gait. High gait variability reflects the loss of gait regulation and predicts mobility decline and falls, which may reveal systemic vulnerability. Thus, w...

BACKGROUND To date, there is no consensus regarding cardiovascular risk management in the very old. Studies have shown that the relationship between traditional cardiovascular risk factors and mortality is null or even inverted within this age group. This relationship could be modified by the presence of frailty. This study was performed to examine the effect of frailty on the association betwe...