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Questions tagged [cox-regression]

The term Cox regression model (omitting proportional hazards) is sometimes used to describe the extension of the Cox model to include time-dependent factors. However, this usage is potentially ambiguous since the Cox proportional hazards model can itself be described as a regression model.

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Loop through a list of variables to add to a base survival model then keep the key output in a table

Two-part question: Firstly, I have a list of n variables in a data frame that I want to sequentially substitute into a survival model (thus creating n new models), and from the output of each, I want to retain only the summary table line (HR, SE's…
C. W.
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coxme proportional hazard assumption

I am running mixed effect Cox models using the coxme function {coxme} in R, and I would like to check the assumption of proportional hazard. I know that the PH assumption can be verified with the cox.zph function {survival} on cox.ph model. However,…
user3637399
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Cox proportional model w/ multiple failures for same subjects

I have a data set that I'm trying to model using survival analysis, specifically cox proportional hazard models. The data has patient IDs and several attributes about the patients (including time till failure). Due to the nature of the data, a…
khaled
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How to create cox proportional chart in R plotly package

I have created a cox proportion plot using ggsurvfit function. Using autoplot package, i convert it into a ggplot chart. Upon applying ggplotly function on it does not work. Says does not support such functions. Please help
user40465
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Q: How to calculate p-values in Cox PH model with maximal test statistic in R?

I am interested in calculating p-values within a Cox PH model based upon the maximal test statistic, to get very robust estimates. Does anyone have experience with this? I have played around a bit with the R package 'coxphf' that incorporates…
Ryon
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Cox PH modeling and prediction with time varying dependency

I have some questions regarding the use of coxph() and predict(Surv()). I am aware that my question is a bit long one and maybe I have not explained myself well enough but any comment or suggestion is appreciated. I am trying to make a Cox PH model…
Peter S
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survfit.coxph: what is the newdata argument?

I do not understand what the newdata argument means. Can someone explain this to me please? I have read the documentation but honestly I just can't understand it. When do I need to use it?
user798719
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How to get Cox p-value for each gene?

If you run the following code, you will have a data frame real.dat which has 1063 samples for 20531 genes. There are 2 extra columns named time and event where time is the survival time and event is death in case of 1 and 0 in case of…
nafizh
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How to find AIC values for both models using R software?

I'm studying survival analysis. I estimated both Cox regression model and Buckley&James regression model. In order to determine which model is better for my dataset, I used Akaike Information Criteria (AIC). Well, How to find AIC values for both…
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Factor covariate violates proportional hazards assumption in coxph model in R

I'm returning to a topic that was addressed by this question a number of months ago. I have a coxph model that includes a factor covariate (a categorical variable) with three levels. When I test the model for violations of the proportional hazards…
Conor Little
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Cox regression in MATLAB

I know there is COXPHFIT function in MATLAB to do Cox regression, but I have problems understanding how to apply it. 1) How to compare two groups of samples with survival data in days (survdays), censoring (cens) and some predictor value (x)? The…
yuk
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Coxph, invalid 'envir' argument of type 'character'

I'm using the Survival package to do a cox regression (coxph) and I can't work out what I'm doing wrong. My code is prentice.fit <- coxph(Surv(age_ent, outage, diabetes) ~ a_menopause + cluster(id), data="mydata.cc",…
Claire 'Scotty' Bear
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R: cox regression power?

I am trying to find out, whether I have enough power to conduct a Cox proportional hazards model using R. My predictor is intelligence and my outcome is cancer. My sample size is 22,000 and I predict 600 cancer cases over 25 years. Furthermore, I…
Len
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How to Adjust restricted cubic spline cox model using rms package?

I am trying to plot a restricted cubic spline model using the rms package. However I don't find any way to adjust my cox proportional hazard model, I can only get the unadjusted fit. Here is my code: library(survival) library(rms) dd <-…
Paola
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smcure package error

I would like to perform a cure analysis, and when I run the code below: pd <- smcure(Surv(FAILTIME,FAILCENS)~trt+Age1 , cureform =~trt+Age1 ,data=saba, model="ph",nboot=1000) This error is reported: Error in rep(1, n) : invalid 'times' argument
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