Displaying 20 results from an estimated 1000 matches similar to: "censoring"
2007 May 01
7
logrank test
how do l programme the logrank test. l am trying to compare 2 survival curves
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2007 May 16
2
log rank test p value
How can I get the Log - Rank p value to be output?
The chi square value can be output, so I was thinking if I can also have the
degrees of freedom output I could generate the p value, but can't see how to
find df either.
> (survtest <- survdiff(Surv(time, cens) ~ group, data = surv,rho=0))
Call:
survdiff(formula = Surv(time, cens) ~ group, data = surv, rho = 0)
N Observed
2011 Jun 24
1
UnoC function in survAUC for censoring-adjusted C-index
Hello,
I am having some trouble with the 'censoring-adjusted C-index' by Uno et al, in the package survAUC. The relevant function is UnoC.
The question has to do with what happens when I specify a time point t for the upper limit of the time range under consideration (we want to avoid using the right-end tail of the KM curve).
Copying from the example in the help file:
TR <-
2009 Mar 30
1
Possible bug in summary.survfit - 'scale' argument ignored?
Hi all,
Using:
R version 2.8.1 Patched (2009-03-07 r48068)
on OSX (10.5.6) with survival version:
Version: 2.35-3
Date: 2009-02-10
I get the following using the first example in ?summary.survfit:
> summary( survfit( Surv(futime, fustat)~1, data=ovarian))
Call: survfit(formula = Surv(futime, fustat) ~ 1, data = ovarian)
time n.risk n.event survival
2012 Jun 28
3
Sobre survival analysis
Hola
Estoy tratando de correr un survival analysis usando un Cox regression model.
Tengo una duda respecto a la organizacion del script. Tengo una variable que es -tamano del individuo- y quiero ver si hay diferencia en sobrevivencia respecto a tamano. Como diseno de campo los tamanos fueron ubicados de forma aleatoria en bloques al azar.
Cuado planteo el script tengo algo como:
2009 Nov 13
2
survreg function in survival package
Hi,
Is it normal to get intercept in the list of covariates in the output of survreg function with standard error, z, p.value etc? Does it mean that intercept was fitted with the covariates? Does Value column represent coefficients or some thing else?
Regards,
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tmp = survreg(Surv(futime, fustat) ~ ecog.ps + rx, ovarian,
2007 Jan 23
1
Estimate and plot hazard function using "muhaz" package
Dear R users,
I am trying to use "muhaz" and "plot.muhaz" functions in "muhaz" package to
estimate and plot hazard funciton. However function "muhaz" always gives
error message "Error in Surv(times, delta) : object "times" not found". I
could not even run their sample codes in the user's manual as follows:
data(ovarian)
2018 May 24
1
Predictions from a Cox model - understanding centering of binary/categorical variables
Dear all,
I am using R 3.4.3 on Windows 10. I am preparing some teaching materials and I'm having trouble matching the by-hand version with the R code.
I have fitted a Cox model - let's use the ovarian data as an example:
library(survival)
data(ovarian)
ova_mod <- coxph(Surv(futime,fustat)~age+rx,data=ovarian)
If I want to make predict survival for a new set of individuals at 100
2005 Nov 27
1
the output of coxph
Dear All:
I have some questions about the output of coxph.
Below is the input and output:
----------------------------------------
> coxph(formula = Surv(futime, fustat) ~ age + rx + ecog.ps, data =
+ ovarian, x = TRUE)
Call:
coxph(formula = Surv(futime, fustat) ~ age + rx + ecog.ps, data =
ovarian, x = TRUE)
coef exp(coef) se(coef) z p
age 0.147 1.158
2007 Dec 07
1
Make natural splines constant outside boundary
Hi,
I'm using natural cubic splines from splines::ns() in survival
regression (regressing inter-arrival times of patients to a queue on
queue size). The queue size fluctuates between 3600 and 3900.
I would like to be able to run predict.survreg() for sizes <3600 and
>3900 by assuming that the rate for <3600 is the same as for 3600 and
that for >4000 it's the same as for
2009 Feb 06
1
Using subset in validate() in Design, what is the correct syntax?
Hi
I am trying to understand how to get the validate() function in Design
to work with the subset option. I tried this:
ovarian.cph=cph(Surv(futime, fustat) ~ age+factor(ecog.ps)+strat(rx),
time.inc=1000, x=T, y=T, data=ovarian)
validate(ovarian.cph)
#fine when no subset is used, but the following two don't work:
> validate(ovarian.cph, subset=ovarian$ecog.ps==2)
Error in
2011 Oct 01
4
Is the output of survfit.coxph survival or baseline survival?
Dear all,
I am confused with the output of survfit.coxph.
Someone said that the survival given by summary(survfit.coxph) is the
baseline survival S_0, but some said that is the survival S=S_0^exp{beta*x}.
Which one is correct?
By the way, if I use "newdata=" in the survfit, does that mean the survival
is estimated by the value of covariates in the new data frame?
Thank you very much!
2004 Dec 06
1
The survival rate at a certain time
Hello there,
I am doing analysis on survival data. How do I pick out a probability of
survival at a chosen landmark time(for example, 3 years, 4 years) from
the result of "survfit"? or any other functions? As I know, the result
of 'survfit' only have the probabilities for all event or cencor time.
Thank you very much
Lisa Wang
Princess Margaret Hospital
Toronto, Ca
tel:
2009 Aug 01
2
Cox ridge regression
Hello,
I have questions regarding penalized Cox regression using survival
package (functions coxph() and ridge()). I am using R 2.8.0 on Ubuntu
Linux and survival package version 2.35-4.
Question 1. Consider the following example from help(ridge):
> fit1 <- coxph(Surv(futime, fustat) ~ rx + ridge(age, ecog.ps, theta=1), ovarian)
As I understand, this builds a model in which `rx' is
2020 Sep 29
5
2 KM curves on the same plot
Hello,
Can anyone suggest a simple way to generate a Kaplan-Meier plot with 2 survfit objects, just like this one:?
https://drive.google.com/file/d/1fEcpdIdE2xYtA6LBQN9ck3JkL6-goabX/view?usp=sharing
Suppose I have 2 survfit objects: fit1 is for the curve on the left (survtime has been truncated to the cutoff line: year 5), fit2 is for the curve on the right (minimum survival time is at the
2009 Apr 14
1
Function call error in cph/survest (package Design)
Dear UseR,
I do not know if this a problem with me, my data or cph/survest in package
design. The example below works with a standard data set, but not with my
data, but I cannot locate the problem.
Note that I am using an older package of survival to avoid a problem with
the newly renamed function in survival meeting Design.
Dieter
# First, check standard example to make sure
library(Design)
2007 May 02
2
missing package
l'm trying to find the "survdiff" package/function but it seems i cant get it how do l instal it if its not there
thanks
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2010 Oct 30
1
two group cox model
Dear all,
I am doing
library(survival)
fit <- coxph(Surv(futime,fustat) ~ rx, ovarian)
plot(survfit(fit,newdata=ovarian),col=c(1,2))
legend("bottomleft", legend=c("rx = 0", "rx = 1"),
lty=c(1,2),col=c(1,2))
Is this correct to compare these two groups? Is the 0.31 the p-value that
the median f two groups are equal
Why lty does not work here?
Many thanks
2012 Nov 27
4
Fitting and plotting a coxph with survfit, package(surv)
Hi Dear R-users
I have a database with 18000 observations and 20 variables. I am running
cox regression on five variables and trying to use survfit to plot the
survival based on a specific variable without success.
Lets say I have the following coxph:
>library(survival)
>fit <- coxph(Surv(futime, fustat) ~ age + rx, data = ovarian)
>fit
what I am trying to do is plot a survival
2005 Sep 13
1
coxph.detail() does not work
Hello everyone,
I tried to use coxph.detail() to get the hazard function. But a warning
messge always returns to me, even in the example provided by its help
document:
> ?coxph.detail
> fit <- coxph(Surv(futime,fustat) ~ age + rx + ecog.ps, ovarian, x=TRUE)
> fitd <- coxph.detail(fit)
Warning message:
data length [37] is not a sub-multiple or multiple of the number of
rows