Displaying 20 results from an estimated 4000 matches similar to: "Hazard function or cumulative Hazard function in R"
2011 Oct 06
1
non-cumulative hazard in Cox model with time-dependent covariates
Dear all,
Is there a way to calculate the non-cumulative hazard (instantaneous
hazard), which is the product of baseline hazard and exp{beta*covariate} ?
I knew in survfit, we can get the estimator of cumulative baseline hazard,
but how can we get the non-cumulative one?
Thank you very much!
Koshihaku
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2006 Mar 07
1
breslow estimator for cumulative hazard function
Dear R-users,
I am checking the proportional hazard assumption of a cox model for a
given covariate, let say Z1, after adjusting for other relavent covariates
in the model. To this end, I fitted cox model stratified on the discrete
values of Z1 and try to get beslow estimator for the baseline cumulative
hazard function (H(t)) in each stratum. As far as i know, if the
proportionality assumption
2009 Jun 20
1
Plotting Cumulative Hazard Functions with Strata
Hello:
So i've fit a hazard function to a set of data using
kmfit<-survfit(Surv(int, event)~factor(cohort))
this factor variable, "cohort" has four levels so naturally the strata
variable has 4 values.
I can use this data to estimate the hazard rate
haz<-n.event/n.risk
and calculate the cumulative hazard function by
H<--log(haz)
Now, I would like to plot this
2009 Feb 23
1
predicting cumulative hazard for coxph using predict
Hi
I am estimating the following coxph function with stratification and frailty?where each person had multiple events.
m<-coxph(Surv(dtime1,status1)~gender+cage+uplf+strata(enum)+frailty(id),xmodel)
?
> head(xmodel)
id enum dtime status gender cage uplf
1 1008666 1 2259.1412037 1 MA 0.000 0
2 1008666 2 36.7495023 1 MA 2259.141 0
3 1008666
2009 May 04
1
Nelson-Aalen estimator of cumulative hazard
Hi,
I am computing the Nelson-Aalen (NA) estimate of baseline cumulative hazard in two different ways using the "survival" package. I am expecting that they should be identical. However, they are not. Their difference is a monotonically increasing with time. This difference is probably not large to make any impact in the application, but is annoyingly non-trivial for me to just
2004 Jul 04
2
smooth non cumulative baseline hazard in Cox model
Hi everyone.
There's been several threads on baseline hazard in Cox model but I think
they were all on cumulative baseline hazard,
for instance
http://tolstoy.newcastle.edu.au/R/help/01a/0464.html
http://tolstoy.newcastle.edu.au/R/help/01a/0436.html
"basehaz" in package survival seems to do a cumulative hazard.
extract from the basehaz function:
sfit <- survfit(fit)
H
2011 Oct 05
0
How to get the hazard of coxph (not cumulative hazard)
Dear all,
I think the coxph and survfit.coxph can give the cumulative hazard of cox
model.
But is there any method to calculate the hazard
Lambda(t)=lambda_0(t)*exp{beta*X(t)}?
Any suggestion will be great help.
Thank you very much!
Koshihaku
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2011 Jun 16
0
coxph: cumulative mortality hazard over time with associated confidence intervals
Dear R-users,
I computed a simple coxph model and plotted survival over time with
associated confidence intervals for 2 covariate levels (males and
females).
M1 <- coxph(survobject~sex, data=surv)
M1
survsex <- survfit(survobject~sex,data=surv)
summary(survsex)
plot(survsex, conf.int=T, col=c("black","red"), lty = c(1,2),
lwd=c(1,2), xlab="Time",
2013 Apr 11
0
plotting the cumulative hazard function of a process whose intensity function is specified
I would like to simulate a stochastic process by specifying an intensity function, say
lambda(t)=0.05 + 3 exp(鈭抰)
I have the following code, but it has a number of problems. One issue I have is I do not know where the time variable is. I would appreciate your help with this code.
library("survival")
n <- 5000
lamc<-0.08
k1<-0.05
k2<-3
ld<-function(t){k1+k2}
2003 Jul 11
2
hazard estimate
Dear list,
is there a function available which provides an estimate of the hazard
function
based on a cox proportional hazard model? I only found the cumulative
hazard and the survival function as survfit options.
Thanks for your help
Peter
2005 Jun 10
1
Estimate of baseline hazard in survival
Dear All,
I'm having just a little terminology problem, relating the language used in
the Hosmer and Lemeshow text on Applied Survival Analysis to that of the
help that comes with the survival package.
I am trying to back out the values for the baseline hazard, h_o(t_i), for
each event time or observation time.
Now survfit(fit)$surv gives me the value of the survival function,
S(t_i|X_i,B),
2001 Feb 22
3
[newbie] Cox Baseline Hazard
Hello everybody.
First of all, I would like to present myself.
I'm a french student in public health and I like statistics though I'm
not that good in mathematics (but I try to catch up). I've discovered R
recently while trying to find a statistical program in order to avoid
rebooting my computer under windows when I need to do some statistical
work.
And here is my first question.
2009 Mar 14
1
obtaining the values for the hazard function in a cox regression
Hello ,
I am hoping for some advice regarding obtaining the values for the
hazard function in a cox regression that I have undertaken. I have a
model in the following form, analysed with the package survival (v.
2.34-1) and a log-log plot obtained using Design (v. 2.1-2).
For two variables, the lines in the survival curves crossed. The
statistician I been obtaining advice from (who does not
2006 Jul 07
6
parametric proportional hazard regression
Dear all,
I am trying to find a suitable R-function for
parametric proportional hazard regressions. The
package survival contains the coxph() function which
performs a Cox regression which leaves the base hazard
unspecified, i.e. it is a semi-parametric method. The
package Design contains the function pphsm() which is
good for parametric proportional hazard regressions
when the underlying base
2012 Jul 06
1
How to compute hazard function using coxph.object
My question is, how to compute hazard function(H(t)) after building the
coxph model. I even aware of the terminology that differs from hazard
function(H(t)) and the hazard rate(h(t)). Here onward I wish to calculate
both.
Here what I have done in two different methods;
##########################################################################################
2012 Feb 20
1
Reporting Kaplan-Meier / Cox-Proportional Hazard Standard Error, km.coxph.plot, survfit.object
What is the best way to report the standard error when publishing
Kaplan-Meier plots? In my field (Vascular Surgery), practitioners
loosely refer to the "10% error" cutoff as the point at which to stop
drawing the KM curve. I am interpreting this as the *standard error
of the cumulative hazard*, although I'm having a difficult time
finding some guidelines about this (perhaps I am
2008 Apr 09
2
How to estimate a hazard ratio using an external hazard function
Hi,
I would like to compare the hazard functions of two samples using the
Cox proportional hazards model. For sample 1 I have individual time-to-
event data. For sample 2 I don't have individual data, but grouped
data that allows to obtain a hazard function.
I am wondering if there is an R function that allows to obtain a
hazard ratio of the two hazard funtions (under the
2010 Nov 15
1
Proportional hazard model with weibull baseline hazard
Dear R-users,
I would like to fit a fully parametric proportional hazard model with a
weibull baseline hazard and a logit link function. This is, the hazard
function is: lambda_i (t) = lambda_0 (t) psi (x_i* beta)
where lambda_0 is a weibull distribution and psi a logistic distribution.
Does someone know a package and/or function on R to do this?
Thanks.
--
M.L. Avendaño
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2007 Dec 18
1
hazard ratio of interaction Cox model
Dear Forum,
I have a question about interaction estimate in the Cox model:
why the hazard ratio of the interaction is not produced in the summary of the model?
(Instead, the estimate of the coefficient is given in the print of the model.)
# Example:
modINT <-cph( Surv(T_BASE, T_FIN,STATUS)~ NYHA + ASINI + RFP + FE_REC + XX_PR*XX_DISF)
print(modINT)
coef se(coef) z
2013 Sep 22
2
[LLVMdev] how to detect data hazard in pre-RA-sched
hi, LLVM,
I found there is a flag DisableHazardRecognizer in TargetInstrImpl.cpp. I
still don't understand how llvm detects data hazard in pre-RA-sched.
pre-RA-sched is based on SDNode and all operands are vregs. Even you can
calculate the operators of SDNodes, the data hazard in vreg are not same as
physical register data hazard. Is it useful to optimize processor pipeline?
thanks,
--lx