|
|
|
|
|
| Gutierrez, Roberto G.. |
| Frailty models are the survival data analog to regression models, which account for heterogeneity and random effects. A frailty is a latent multiplicative effect on the hazard function and is assumed to have unit mean and variance θ, which is estimated along with the other model parameters. A frailty model is an heterogeneity model where the frailties are assumed to be individual- or spell-specific. A shared frailty model is a random effects model where the frailties are common (or shared) among groups of individuals or spells and are randomly distributed across groups. Parametric frailty models were made available in Stata with the release of Stata 7, while parametric shared frailty models were made available in a recent series of updates. This article... |
| Tipo: Journal Article |
Palavras-chave: Parametric survival analysis; Frailty; Random effects; Overdispersion; Heterogeneity; Research Methods/ Statistical Methods. |
| Ano: 2002 |
URL: http://purl.umn.edu/115948 |
| |
|
|
| Pinto Neto,Lauro Ferreira da Silva; Sales,Marina Cerqueira; Scaramussa,Eduarda Sobral; da Paz,Clara Junia Calazans; Morelato,Renato Lirio. |
| Abstract Presarcopenia and sarcopenia were evaluated in HIV-infected individuals and in healthy elderly controls according to the consensus definitions of the European Working Group on Sarcopenia in Older People. Bioelectrical impedance, a hydraulic hand dynamometer, and gait speed were used to evaluate muscle mass, muscle strength, and physical performance, respectively. Adjusted and unadjusted binary logistic regression predicted the risk of sarcopenia. Predictor contribution was assessed by the Wald test. Significance was established at p ≤ 0.05. The HIV-infected group consisted of 33 patients on treatment (42.4% women; mean age 59 ± 7 years; mean BMI 25 ± 6 kg/m2; viral load undetectable in 30 cases). The HIV-uninfected group consisted of 60... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Sarcopenia; HIV; Frailty. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702016000100099 |
| |
|
|
| Buto,M.S.S.; Catai,A.M.; Vassimon-Barroso,V.; Gois,M.O.; Porta,A.; Takahashi,A.C.M.. |
| Frailty is related to a decrease in the physiological reserves, which causes difficulties in maintaining homeostasis. An example of physiological mechanisms for cardiovascular homeostasis is the baroreflex. The aim of this study was to compare baroreflex among frail, prefrail, and nonfrail individuals, in supine and orthostatic positions. Community-dwelling older adults were evaluated and categorized into frail, prefrail, or nonfrail groups, according to frailty phenotype. The RR interval (RRi) and systolic blood pressure (SBP) series were recorded for 15 min in the supine and 15 min in the orthostatic positions. Mean and variance of RRi and SBP, and baroreflex evaluated by phase, gain (α), and coherence (K2) were determined. A two-way repeated measures... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Baroreflex; Autonomic nervous system; Aging; Frailty. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2019000400602 |
| |
|
|
|
