proportional hazards assumption was not violated. In studies with a case cohort design, all Cox proportional hazards models were Prentice weighted. We modeled polygenic risk score, total or subtypes of fat intake, and the interaction terms as continuous variables. We used polynomials to investigate ...
When the proportional hazards assumption is violated the hazard ratio is ill-defined and the power of the log-rank test depends on the distribution of the censoring times. The average hazard ratio was proposed as an alternative effect measure, which has a meaningful interpretation in the case of...
With explanatory covariates, the standard analysis for competing risks data involves modeling the cause-specific hazard functions via a proportional hazards assumption. Unfortunately, the cause-specific hazard function does not have a direct interpretation in terms of survival probabilities for the particular...
However, when the absolute change in risk, instead of the risk ratio, is of primary interest or when the proportional hazard assumption for Cox proportional hazards model is violated, an additive hazard regression model may be more appropriate (Xie et al., 2013). Frailty models are extensively...
nonproportional hazardsThe Cox model was originally built upon the proportional hazards (PH) assumption that is often violated in reality. When the PH assumption for a covariate is not satisfied, the Cox model estimates the overall effect of the covariate within the follow-up period, but the ...
I'm trying to check that the proportional hazards assumption is satisfied with all my variables in my Cox model. I used 2 methods to do this, but they give different results. First method: Add time-dependent variable to the original model (in this case, a product of a variable o...
However, it may be suboptimal due to the inflexibility to model the baseline survival function and when the proportional hazards assumption is violated. The aim of this study was to use internal validation to compare the predictive power of a flexible Royston-Parmar family of survival functions ...
Also, this situation causes the proportional hazards assumption to be violated especially in Cox regression analysis. Outlier(s) are identified with the help... O Demir,N Erkorkmaz - 《Sakarya Tp Dergisi》 被引量: 0发表: 2024年 Estimating and modelling cumulative incidence functions using time-...
The log-rank test and the Cox proportional hazards model are commonly used to compare time-to-event data in clinical trials, as they are most powerful under proportional hazards. But there is a loss of power if this assumption is violated, which is the case for some new oncology drugs like...
Sasieni, Evaluation of long-term survival: use of diagnostics and robust estimators with Cox's proportional hazards model. Stat. Med., 1996. 15(24): p. 2763-80.Valsecchi MG, Silvestri D, Sasieni P. Evaluation of long-term survival: use of diagnostics and robust estimators with Cox’s...