Displaying 20 results from an estimated 1000 matches similar to: "Age as time-scale in a cox model"
2009 Feb 18
1
Age as time-scale in a cox model-How to calculate x-time risk?
Dear R users,
My question is more methodology related rather than specific to R usage. Using time on study as time in a cox model, eg:
library(Design)
stanf.cph1=cph(Surv(time, status) ~ t5+id+age, data=stanford2, surv=T)
#In this case the 1000-day survival probability would be:
stanf.surv1=survest(stanf.cph1, times=1000)
#Age in this case is a covariate.
#I now want to compare the above
2009 Oct 13
1
Time Dependent Cox Model
I am having trouble formatting some survival data to use in a time dependent
cox model. My time dep. variable is habitat and I have it recorded for every
day (with some NAs). I think it is working properly except for calculating
the death.time. This column should be 1s or 0s and as I have it only
produces 0s. Any help will be greatly appreciated.
2009 Apr 23
0
Cox regression
Hi
I am doing a survival analysis and have run into a couple of things that I was hoping I could get some advice on.
The first thing is that when I run an ordinary Cox regression in R I get the same results that I do using Stata (provided that I specify the Efron method for handling ties) but I also get the following warning message:
"Warning message:
In coxph(Surv1 ~ Out + site + haem) :
2006 Aug 02
0
expected survival from a frailty cox model using survfit
Hello R users
Would somebody know how to estimate survival from a frailty cox model,
using the function survfit
and the argument newdata ? (or from any other way that could provide
individual expected survival
with standard error); Is the problem related to how the random term is
included in newdata ?
kfitm1 <- coxph(Surv(time,status) ~ age + sex + disease + frailty(id,
2007 Jun 08
0
Escobar&Meeker example survreg
Dear all,
I am new to R and may make beginner mistakes. Sorry.
I am learning using R to do survival analysis. As a start I used the
example script code provided in the documentation of predict.survreg of
the survival package:
# Draw figure 1 from Escobar and Meeker
fit <- survreg(Surv(time,status) ~ age + age^2, data=stanford2,
dist='lognormal')
plot(stanford2$age, stanford2$time,
2015 Aug 02
3
ayuda con análisis de supervivencia
Hola a todos,
-Estoy estudiando el efecto de dos genotipos (~tratamientos) en la aparición de síndrome metabólico (MetS) con datos longitudinales recogidos a tiempo 0,7,10,15,20 y 25 años.
-He hecho un dataframe con las siguientes variables
MetS: Síndrome Metabólico (Si=1,No=0)
bmi: Indice de masa corporal (IMC) cuando se produce la conversión a MetS+ . Para los que permancen MetS-, esta variable
2008 Feb 28
0
surv2sample 0.1-2
Dear useRs,
There is a new version 0.1-2 of the package surv2sample available on CRAN.
Users of the previous versions should update because a bug in the function
cif2.ks has been fixed.
General information about the package:
surv2sample provides various two-sample tests for right-censored survival
data. Three main areas and corresponding methods are:
* comparison of two survival
2008 Feb 28
0
surv2sample 0.1-2
Dear useRs,
There is a new version 0.1-2 of the package surv2sample available on CRAN.
Users of the previous versions should update because a bug in the function
cif2.ks has been fixed.
General information about the package:
surv2sample provides various two-sample tests for right-censored survival
data. Three main areas and corresponding methods are:
* comparison of two survival
2013 Jun 25
1
censor=FALSE and id options in survfit.coxph
Terry,
I recently noticed the censor argument of survfit. For some analyses it greatly reduces the size of the resulting object, which is a nice feature.
However, when combined with the id argument, only 1 prediction is made. Predictions can be made individually but I'd prefer to do them all at once if that change can be made.
Chris
#####################################
# CODE
# create
2008 May 09
2
how to check linearity in Cox regression
Hi, I am just wondering if there is a test available for testing if a linear fit of an independent variable in a Cox regression is enough? Thanks for any suggestions.
John Zhang
____________________________________________________________________________________
[[elided Yahoo spam]]
2011 Sep 05
1
SAS code in R
Dear all,
I was wondering if anyone can help? I am an R user but recently I have resorted to SAS to calculate the probability of the event (and the associated confidence interval) for the Cox model with combinations of risk factors. For example, suppose I have a Cox model with two binary variables, one for gender and one for treatment, I wish to calculate the probability of survival for the
2006 Oct 25
1
Incorrect 'n' returned by survfit()
I've a data set with 60000 rows of data representing 6000+ distinct loans. I did a coxph() regression on it (see call below), but a subsequent survfit() call on the coxph object is almost certainly wrong. It gives n=6 when it should be
more like 6000+ (I think)
> survfit(resultag)
Call: survfit.coxph(object = resultag)
n events median 0.95LCL 0.95UCL
6 489 Inf
2006 Mar 08
1
RES: survival
Dear Thomas,
The head of my dataset
> head(wsuv)
parcel sp time censo treatment
species
1 S8 Poecilanthe effusa ( Hub. ) Ducke. 1 1 1 1
2 S8 Poecilanthe effusa ( Hub. ) Ducke. 1 1 1 1
3 S8 Poecilanthe effusa ( Hub. ) Ducke. 1 1 1 1
4 S8 Poecilanthe effusa ( Hub. ) Ducke. 1 1 1
2007 Dec 09
2
Getting estimates from survfit.coxph
Dear all,
I'm having difficulty getting access to data generated by survfit and
print.survfit when they are using with a Cox model (survfit.coxph).
I would like to programmatically access the median survival time for
each strata together with the 95% confidence interval. I can get it on
screen, but can't get to it algorithmically. I found myself examining
the source of print.survfit to
2004 Nov 17
1
frailty and time-dependent covariate
Hello,
I'm trying to estimate a cox model with a frailty variable and time-dependent covariate (below there is the statement I use and the error message). It's seems to be impossible, because every time I add the time-dependent covariate the model doesn't converge. Instead, if I estimate the same model without the time-dependent covariate it's converge. I'd like knowing if
2010 Nov 24
2
Is there an equivalent to predict(..., type="linear") of a Proportional hazard model for a Cox model instead?
Hi all,
Is there an equivalent to predict(...,type="linear") of a Proportional hazard
model for a Cox model instead?
For example, the Figure 13.12 in MASS (p384) is produced by:
(aids.ps <- survreg(Surv(survtime + 0.9, status) ~ state + T.categ +
pspline(age, df=6), data = Aidsp))
zz <- predict(aids.ps, data.frame(state = factor(rep("NSW", 83), levels =
2024 May 15
2
Extracting values from Surv function in survival package
OS X
R 4.3.3
Colleagues
I have created objects using the Surv function in the survival package:
> FIT.1
Call: survfit(formula = FORMULA1)
n events median 0.95LCL 0.95UCL
SUBDATA$ARM=1, SUBDATA[, EXP.STRAT]=0 18 13 345 156 NA
SUBDATA$ARM=2, SUBDATA[, EXP.STRAT]=1 13 5 NA 186 NA
SUBDATA$ARM=2, SUBDATA[, EXP.STRAT]=2 5
2024 May 16
1
Extracting values from Surv function in survival package
Hi Dennis,
look at the help page for summary.survfit, the Value n.event.
G?ran
On 2024-05-15 22:41, Dennis Fisher wrote:
> OS X
> R 4.3.3
>
> Colleagues
>
> I have created objects using the Surv function in the survival package:
>> FIT.1
> Call: survfit(formula = FORMULA1)
>
> n events median 0.95LCL 0.95UCL
>
2010 Jul 28
1
anderson-darling test
Hi,
I have the binned data (observed and generated from model) that I would like to
test using the anderson-darling goodness of fit test. But I'm not sure which
package in R to use.
I tried ad.test(...) but it does not recognise the test by Vito Ricci in FITTING
DISTRIBUTIONS WITH R
> ad.test(hist_hume_beec[,1],hist_hume_beec[,2])
Error: could not find function "ad.test"
2011 Mar 18
1
median survival time from survfit
Hello,
I am trying to compute the mdeian of the survival time from the function
survfit:
> fit <- survfit(Surv(time, status) ~ 1)
> fit
Call: survfit(formula = Surv(time, status) ~ 1)
records n.max n.start events median 0.95LCL 0.95UCL
111 111 111 20 NA NA NA
The results is NA? the fit$surv gives values between 1 and 0.749! Am I doing
this correct?