Results 21 to 30 of about 784,290 (230)

Using fractional polynomials and restricted cubic splines to model non‐proportional hazards or time‐varying covariate effects in the Cox regression model

open access: yesStatistics in Medicine, 2021
The Cox proportional hazards model is used extensively in clinical and epidemiological research. A key assumption of this model is that of proportional hazards.
P. Austin, Jiming Fang, Douglas S. Lee
semanticscholar   +1 more source

Identification of a competing risks model with unknown transformations of latent failure times [PDF]

open access: yes, 2005
This paper is concerned with identification of a competing risks model with unknown transformations of latent failure times. The model in this paper includes, as special cases, competing risks versions of proportional hazards, mixed proportional ...
Berwanger, Dietmar   +4 more
core   +7 more sources

Comparison of regression imputation methods of baseline covariates that predict survival outcomes

open access: yesJournal of Clinical and Translational Science, 2021
Introduction: Missing data are inevitable in medical research and appropriate handling of missing data is critical for statistical estimation and making inferences.
Nicole Solomon   +2 more
doaj   +1 more source

Application of random survival forests in understanding the determinants of under-five child mortality in Uganda in the presence of covariates that satisfy the proportional and non-proportional hazards assumption

open access: yesBMC Research Notes, 2017
Background Uganda just like any other Sub-Saharan African country, has a high under-five child mortality rate. To inform policy on intervention strategies, sound statistical methods are required to critically identify factors strongly associated with ...
Justine B. Nasejje, Henry Mwambi
doaj   +1 more source

Testing proportional hazards for specified covariates

open access: yesModern Stochastics: Theory and Applications, 2019
Tests for proportional hazards assumption concerning specified covariates or groups of covariates are proposed. The class of alternatives is wide: log-hazard rates under different values of covariates may cross, approach, go away.
Vilijandas Bagdonavičius   +1 more
doaj   +1 more source

Generating Survival Times to Simulate Cox Proportional Hazards Models [PDF]

open access: yes, 2003
This paper discusses techniques to generate survival times for simulation studies regarding Cox proportional hazards models. In linear regression models, the response variable is directly connected with the considered covariates, the regression ...
Augustin, Thomas   +2 more
core   +2 more sources

Simulating time-to-event data under the Cox proportional hazards model: assessing the performance of the non-parametric Flexible Hazards Method

open access: yesFrontiers in Applied Mathematics and Statistics, 2023
Numerous methods and approaches have been developed for generating time-to-event data from the Cox Proportional Hazards (CPH) model; however, they often require specification of a parametric distribution for the baseline hazard even though the CPH model ...
Jennifer L. Delzeit, Devin C. Koestler
doaj   +1 more source

Bayesian Analysis of Masked Competing Risks Data Based on Proportional Subdistribution Hazards Model

open access: yesMathematics, 2022
Masked issues can emerge when dealing with competing risk data. Such issues are exemplified by the cause of a particular failure not being directly exhibited for all units to observe but only proven to be a subset of possible causes of failure.
Yosra Yousif   +3 more
doaj   +1 more source

Statistical estimation in the proportional hazards model with risk set sampling [PDF]

open access: yes, 2004
Thomas' partial likelihood estimator of regression parameters is widely used in the analysis of nested case-control data with Cox's model. This paper proposes a new estimator of the regression parameters, which is consistent and asymptotically normal ...
Chen, Kani
core   +2 more sources

Comparison of radiomic feature aggregation methods for patients with multiple tumors

open access: yesScientific Reports, 2021
Radiomic feature analysis has been shown to be effective at analyzing diagnostic images to model cancer outcomes. It has not yet been established how to best combine radiomic features in cancer patients with multifocal tumors.
Enoch Chang   +7 more
doaj   +1 more source

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