scholarly journals Flexible modelling of discrete failure time including time-varying smooth effects

2004 ◽  
Vol 23 (15) ◽  
pp. 2445-2461 ◽  
Author(s):  
G. Tutz ◽  
H. Binder
2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Yi Ren ◽  
Chung-Chou H. Chang ◽  
Gabriel L. Zenarosa ◽  
Heather E. Tomko ◽  
Drew Michael S. Donnell ◽  
...  

Transplantation is often the only viable treatment for pediatric patients with end-stage liver disease. Making well-informed decisions on when to proceed with transplantation requires accurate predictors of transplant survival. The standard Cox proportional hazards (PH) model assumes that covariate effects are time-invariant on right-censored failure time; however, this assumption may not always hold. Gray’s piecewise constant time-varying coefficients (PC-TVC) model offers greater flexibility to capture the temporal changes of covariate effects without losing the mathematical simplicity of Cox PH model. In the present work, we examined the Cox PH and Gray PC-TVC models on the posttransplant survival analysis of 288 pediatric liver transplant patients diagnosed with cancer. We obtained potential predictors through univariable(P<0.15)and multivariable models with forward selection(P<0.05)for the Cox PH and Gray PC-TVC models, which coincide. While the Cox PH model provided reasonable average results in estimating covariate effects on posttransplant survival, the Gray model using piecewise constant penalized splines showed more details of how those effects change over time.


Biometrics ◽  
2000 ◽  
Vol 56 (4) ◽  
pp. 996-1001 ◽  
Author(s):  
Corette B. Parker ◽  
Elizabeth R. Belong

Biometrics ◽  
2019 ◽  
Vol 76 (3) ◽  
pp. 799-810
Author(s):  
Yasuhiro Hagiwara ◽  
Tomohiro Shinozaki ◽  
Yutaka Matsuyama
Keyword(s):  

Biometrics ◽  
1998 ◽  
Vol 54 (3) ◽  
pp. 1115 ◽  
Author(s):  
Joanna H. Shih

2019 ◽  
Vol 119 (11) ◽  
pp. 1849-1859 ◽  
Author(s):  
Alberto Carmona-Bayonas ◽  
Paula Jimenez-Fonseca ◽  
Marcelo Garrido ◽  
Ana Custodio ◽  
Raquel Hernandez ◽  
...  

AbstractResearch into cancer-associated thrombosis (CAT) entails managing dynamic data that pose an analytical challenge. Thus, methods that assume proportional hazards to investigate prognosis entail a risk of misinterpreting or overlooking key traits or time-varying effects. We examined the AGAMENON registry, which collects data from 2,129 patients with advanced gastric cancer. An accelerated failure time (AFT) multistate model and flexible competing risks regression were used to scrutinize the time-varying effect of CAT, as well as to estimate how covariates dynamically predict cumulative incidence. The AFT model revealed that thrombosis shortened progression-free survival and overall survival with adjusted time ratios of 0.72 and 0.56, respectively. Nevertheless, its prognostic effect was nonproportional and disappeared over time if the subject managed to survive long enough. CAT that occurred later had a more pronounced prognostic effect. In the flexible competing risks model, multiple covariates were seen to have significant time-varying effects on the cumulative incidence of CAT (Khorana score, secondary thromboprophylaxis, high tumor burden, and cisplatin-containing regimen), whereas other predictors exerted a constant effect (signet ring cells and primary thromboprophylaxis). The model that assumes proportional hazards was incapable of capturing the effect of these covariates and predicted the cumulative incidence in a biased way. This study evinces that flexible and multistate models are a useful and innovative method to describe the dynamic effect of variables associated with CAT and should be more widely used.


2004 ◽  
Vol 58 (3) ◽  
pp. 271-295 ◽  
Author(s):  
Judith Lok ◽  
Richard Gill ◽  
Aad van der Vaart ◽  
James Robins

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