similar to: SAS and R code hazard ratios

Displaying 20 results from an estimated 3000 matches similar to: "SAS and R code hazard ratios"

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
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
2008 Dec 04
1
comparing SAS and R survival analysis with time-dependent covariates
Dear R-help, I was comparing SAS (I do not know what version it is) and R (version 2.6.0 (2007-10-03) on Linux) survival analyses with time-dependent covariates. The results differed significantly so I tried to understand on a short example where I went wrong. The following example shows that even when argument 'method' in R function coxph and argument 'ties' in SAS procedure
2011 Aug 21
3
pooled hazard model with aftreg and time-dependent variables
Dear R-users, I have two samples with individuals that are in more than one of the samples and individuals that are only in one sample. I have been trying to do a pooled hazard model, stacking one sample below the other, with aftreg and time-dependent covariates. The idea behind is to see aggregate effects of covariates, but need to control for ther effects of same individuals in both samples
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
2011 Feb 27
3
nested case-control study
Hi, I am wondering if there is a package for doing conditional logistic regression for nested case-control study as described in "Estimation of absolute risk from nested case-control data" by Langholz and Borgan (1997) where Horvitz-Thompson sampling weight (log of (number in the risk set divided by the number sampled)) is used with regression. In SAS Proc Phreg, this is implemented
2008 Nov 21
1
lsoda warning "too much accuracy requested"
Dear list - Does anyone have any ideas / comments about why I am receiving the following warning when I run lsoda: 1: lsoda-- at t (=r1), too much accuracy requested in: lsoda(start, times, model, parms) 2: for precision of machine.. see tolsf (=r2) in: lsoda(start, times, model, parms) I have tried changing both rtol and atol but without success. I saw the thread in the
2011 Jul 20
0
comparing SAS and R survival analysis with time-dependent covariates
Let me expand a bit on Thomas's answer. Looking more closely at your data set you have the following: death time group 0 group 1 1.5 0/4 13/13 3 0/4 5/5 8 4/4 0 At time 1.5 group 1 had 13 deaths out of 13 at risk, group 0 had none. Time 8 doesn't have any impact on the fit, since only one group
2005 Jun 15
1
anova.lme error
Hi, I am working with R version 2.1.0, and I seem to have run into what looks like a bug. I get the same error message when I run R on Windows as well as when I run it on Linux. When I call anova to do a LR test from inside a function, I get an error. The same call works outside of a function. It appears to not find the right environment when called from inside a function. I have provided
2010 Jan 03
1
Anova in 'car': "SSPE apparently deficient rank"
I have design with two repeated-measures factor, and no grouping factor. I can analyze the dataset successfully in other software, including my legacy DOS version BMDP, and R's 'aov' function. I would like to use 'Anova' in 'car' in order to obtain the sphericity tests and the H-F corrected p-values. I do not believe the data are truly deficient in rank. I
2007 Jul 25
1
Updating packages in Ubuntu feisty for 2.5
Hi, I would like to run R2.5.1 in Ubuntu feisty on an AMD64 chip. I am a total newbie to Linux. I have successfully compiled 2.5 however, I am not able to figure out how to upgrade the packages. I am not able to find an R-base-core_2.5.1-1_amd64 or all on the CRAN mirrors. I can find one on the Ubuntu feisty site, however when I try to install it I get a warning that Dependency is not stisfiable:
2011 Apr 01
2
Cox Proportional Hazards model with a time-varying covariate
Hello Everyone,   I'm learning how to perform various statistical analyses in R. I'm checking my understanding by replicating examples from my SAS books. Below is an attempt to replicate a Cox Proportional Hazards model with a time-varying covariate. I think I'm doing this correctly but am not completely sure. I would appreciate it if someone could double-check my results. In case
2013 Apr 24
2
Trouble Computing Type III SS in a Cox Regression
I should hope that there is trouble, since "type III" is an undefined concept for a Cox model. Since SAS Inc fostered the cult of type III they have recently added it as an option for phreg, but I am not able to find any hints in the phreg documentation of what exactly they are doing when you invoke it. If you can unearth this information, then I will be happy to tell you whether
2007 May 28
1
[1.2.18] Wrong steps in extensions.conf?
Hello, Sometimes, when a call comes in from the PSTN through our VoIP gateway, the information that is sent to our web page that logs calls includes the original CID name instead of the one that is we expect to be rewritten on the fly using Asterisk's LookupCIDName: ================= ;extensions.conf [internal] exten => group,1,LookupCIDName exten =>
2005 Jun 22
1
A question on time-dependent covariates in the Cox model.
I have a dataset with event=death time (from medical examination until death/censoring) dose (given at examination time) Two groups are considered, a non-exposed group (dose=0), an exposed group (dose between 5 and 60). For some reason there is a theory of the dose increasing its effect over time (however it was only given (and measured) once = at the time of examination). I tested a model:
2010 Oct 26
2
Formatting durations
Hi, I am working with a dataset for sometime and I need some help in parsing some data. There is a column called "Duration" which has data like following: 2 minutes => 120 2 min => 120 10 seconds =>10 2 hrs =>7200 2-3 minutes => 150 or 120 5 minutes (when i arrived => 300 Flyby approx 20 sec. => 20 felt like 10 mins but tim => 600 I need to convert them to
2005 Jun 27
1
test of hazard ratios
Hi, Is there a R test available that tests whether 2 hazard ratios obtained from Cox regressions on the same patient sample by 2 different classifiers are significantly different? Thanks Steve
2010 Nov 17
0
Cox model output & hazard ratios
Dear R users, Here is the coxme output I obtain on my survival dataset having 3 strains and 2 infection status (i: infected, ni: non infected) coxme(Surv(lay) ~ infection*strain, data=datalay, random= ~1 |block) Cox mixed-effects model fit by maximum likelihood Data: datalay n= 1194 Iterations= 3 77 NULL Integrated Penalized Log-likelihood -7270.028 -7223.859 -7218.175
2011 Jul 02
0
comparing hazard ratios
hi, I'm looking for a package to compare two hazard ratios (and assign statistical significance) obtained from two different predictive models. I know of the hr.comp2 function from the survcomp package, but was wondering if there's any other packages out there. thanks! [[alternative HTML version deleted]]
2010 Sep 30
2
time in year, month, day, hour ?
Dear R Users, I did not get any reply on my question so I am re-asking. This time I am giving sample data: 1 60.3162 -13.5993 -0.4353 46.0938 0.1877 -0.194E-07 2 60.3713 -13.5992 -0.4423 46.1241 0.2057 -0.231E-06 3 60.3430 -13.5981 -1.6163 44.9048 0.2237 -0.270E-06 4 60.3227 -13.5970 -2.6258 43.8785 0.2213