similar to: About 'hazard ratio', urgent~~~

Displaying 20 results from an estimated 4000 matches similar to: "About 'hazard ratio', urgent~~~"

2010 Mar 09
1
Question on passing in parameter to Cox hazard
Hi, I wanted to do the cox model using a matrix. The following lines illustrate what I want to do: -------------------------------- dat <- matrix(rnorm(30), ncol=3,dimnames = list(1:10,letters[1:3])) Survival <- rexp(10) Status <- ifelse(runif(10) < .7, 1, 0) mat <- as.data.frame(cbind(dat,Survival,Status)) cmod <- coxph(Surv(Survival, Status) ~ a+b+c, mat)
2010 May 25
2
Relative Risk/Hazard Ratio plots for continuous variables
Dear all, I am using Windows and R 2.9.2 for my analyses. I have a large dataset and I am particularly interested in looking at time to an event for a continuous variable. I would like to produce a plot of log(relative risk) or relative risk (also known as hazard ratio) against the continuous variable. I have spent a long time looking for advice on how to do this but my search has proved
2011 Dec 10
2
p-value for hazard ratio in Cox proportional hazards regression?
Hi, I'm new to R and using it for Cox survival analysis. Thanks to this great forum I learned how to compute the HR with its confidence interval. My question would be: Is there any way to get the p-value for a hazard ratio in addition to the confidence interval? Thanks, Thierry -- Thierry Panje Visiting Student Researcher Department of Psychology Stanford
2011 Oct 21
1
cph/nomogram Design/RMS package hazard ratio: interquartile vs per unit
Hello, I am constructing a nomogram using cph and nomogram commands in Dr. Harrell's Design/RMS package. The HR that I obtain for dichotomous and categorical variables are identical to those that I obtain using STATA stcox. However, the inter-quartile HR I obtain for continuous variables is obviously different, since STATA gives me HR for each unit (year, centimeter, etc) like coxph would
2009 Oct 24
1
Generate random variate from a non-parametric hazard function
Hi I have estimated a hazard function using a kernel based method. Now i have to generate a random variate that follows this hazard function. Does any one know method I should use to generate the variate. Thanks Samiul -- View this message in context: http://www.nabble.com/Generate-random-variate-from-a-non-parametric-hazard-function-tp26034880p26034880.html Sent from the R help mailing list
2011 Apr 18
1
time dependent hazard ratios
Hi, I am new to time-dependent Cox model to estimate time dependent hazard ratios. Let me use aml dataset from survival package: > aml3<-survSplit(aml2,cut=c(5,10,20),end="time",start="start", event="status",episode="i") If I want to esimate hazard ratio for each of the time intervals 0-5, 5-10, 10-20 and >=20, would the following calculate
2005 Oct 11
1
summary of Surv object crashes R 2.2.0 (PR#8203)
Full_Name: Victor Moreno Version: 2.2.0 OS: windows Submission from: (NULL) (213.151.99.160) summary of an object class Surv (package survival) hangs and closes R 2.2.0 I would like to have Surv objects in a data frame to build models easier: t<-rexp(100) s<-rbinom(100,1,.3) surv<-Surv(t,s) x1<-rnorm(100,10,2) x2<-rnorm(100,10,2) dat<-data.frame(surv,x1,x2)
2010 Mar 30
5
Problem comparing hazard ratios
Dear R-Helpers, I am a novice in survival analysis. I have the following code: for (i in 3:12) print(coxph(Surv(time, status)~a[,i], data=a)) I used it to fit the Cox Proportional Hazard models separately for every available parameter (columns 3:12) in my data set - with intention to compare the Hazard Ratios. However, some of my variables are in range 0.1 to 1.6, others in range 5000 to
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
2018 Apr 04
1
parfm unable to fit models when hazard rate is small
Hello, I would like to use the parfm package: https://cran.r-project.org/web/packages/parfm/parfm.pdfhttps://cran.r-project.org/web/packages/parfm/parfm.pdf in my work. This package fits parametric frailty models to survival data. To ensure I was using it properly, I started by running some small simulations to generate some survival data (without any random effects), and analyse the data using
2007 Jan 10
2
SAS and R code hazard ratios
Greetings, I am new to R and have been comparing CPH survival analysis hazard ratios between R and SAS PhReg. The binary covariates' HRs are the same, however the continuous variables, for example age, have quite different HRs although in the same direction. SAS PhReg produces HRs which are the change in risk for every one increment change in the independent variable. How do I
2010 Aug 05
2
a question about 'read.table' with or without 'read.table'.(urgent)
Hi, I've got a quite tricky question. I have a txt file, named 'temp.txt', as the following: snp1 snp2 snp3 AA 00 00 GG GG 00 00 AA 00 I want to read the file into R. 1) when I use 'read.table' without 'header=T' option, > temp <- read.table('temp.txt') # I got > temp V1
2011 Jan 26
2
crash when using hazard.ratio.plot from rms package
Dear all, I always encounter a crash when running hazard.ratio.plot from rms package with my predictor as a factor. It works fine when the predictor is a continous score. Anyone encounters this too? Is this a bug or something? Thanks, Lilian [[alternative HTML version deleted]]
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
2005 Jun 22
1
analyzing suvival data using splines (a.k.a., piecewise log-hazard-ratio models)
I'm looking for software that makes plots such as fig 4 (a)-(e), fig 5 anf fig 7 of Gray, Robert, "Flexible Methods for Analyzing Survival Data Using Splines, with Applications to Breast Cancer Prognosis," 1992, J Am Stat Assoc, pp 942-51. In other words, I'm looking for software that takes survival data and a continuous covariate as input and computes a curve giving log hazard
2002 May 03
6
problems with rexp ?
Does anyone know if R have any problems with the exponential random number generation (function rexp)? I comment it because I executed data<-sort(rexp(100)) plot(data,dexp(data)/(1-pexp(data)),type="l") and the graphic isn't constant. (Note: exponential distribution have a constant hazard failure rate). Thank you, Juan
2012 May 11
2
survival analysis simulation question
Hi, I am trying to simulate a regression on survival data under a few conditions: 1. Under different error distributions 2. Have the error term be dependent on the covariates But I'm not sure how to specify either conditions. I am using the Design package to perform the survival analysis using the survreg, bj, coxph functions. Any help is greatly appreciated. This is what I have so far:
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 Oct 11
2
Question on survival
Hi, I'm going crazy trying to plot a quite simple graph. i need to plot estimated hazard rate from a cox model. supposing the model i like this: coxPhMod=coxph(Surv(TIME, EV) ~ AGE+A+B+strata(C) data=data) with 4 level for C. how can i obtain a graph with 4 estimated (better smoothed) hazard curve (base-line hazard + 3 proportional) to highlight the effect of C. thanks!! laudan [[alternative
2006 Jun 14
3
A question about stepwise procedures: step function
Dear all, I tried to use "step" function to do model selection, but I got an error massage. What I don't understand is that data as data.frame worked well for my other programs, how come I cannot make it run this time. Could you please tell me how I can fix it? ***************************************************************************************************