similar to: comparing SAS and R survival analysis with time-dependent covariates

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

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

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:

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

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

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

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

hi. i''ve got a couple migrations where i''ve added foreign keys and tried to update them via the migration but my items don''t save. i''ve used save! in the hopes that an exception gets raised but no luck. the migrations run without errors but the data isn''t in the db. can anyone point out what i might be doing wrong? thanks! code below. class

I tried to compare if cch() and coxph() can generate same result for same case cohort data Use the standard data in cch(): nwtco Since in cch contains the cohort size=4028, while ccoh.data size =1154 after selection, but coxph does not contain info of cohort size=4028. The rough estimate between coxph() and cch() is same, but the lower and upper CI and P-value are a little different. Can we

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

Hi, Can someone tell me how to create .rda data files in R so that they can be used contributed package? Thanks Deli Wang [[alternative HTML version deleted]]

G?ran, thanks for the update, I'm just about to install it! Just wanted to drop you a short line about performance (as you once requested): aftreg takes ages on my windows machine to calculate a small set of 7 observations which are not even grouped together by "id". To be a bit more precise, it takes 2:40 mins on my Intel T9300 Core2 Duo @ 2.5 GHz. Bigger samples with about 700

Hi, I am beginner with R and need firm guidance with my problem. I have seen some other threads discussing the subject of right censored data, but I am not sure whether or not this problem can be regarded as such. Data: I have a vector with laboratory test data (strength of wood specimens, example attached as txt-file). This data is the full sample. It is a common view that this kind of data

All. I am running Xen on an ES7000 system with 4 procs and 4 GB memory. I am running Suse Sles-9 (32-bit) on the machine. I have compiled Xen (the tip on the unstable tree : 6552) with PAE enabled (XEN_TARGET_X86_PAE=y). The system boots fine. I started xend and when I tried to bring up a virtual machine, the system gave me the following error on the command line. On the serial port, I saw an

Hi, I am trying to run a conditional logistic model on a nested case-control study using cph() and then estimate survival based on the model. The data came from Prof Bryan Langholz website where he also has the SAS code to this, so I am trying to replicate the SAS results. The data attached. Basically, the variables are: rstime: risk set age rsentry: fake entry time, just before rstime setno:

--------- begin included message --------- I tried to compare if cch() and coxph() can generate same result for same case cohort data Use the standard data in cch(): nwtco Since in cch contains the cohort size=4028, while ccoh.data size =1154 after selection, but coxph does not contain info of cohort size=4028. The rough estimate between coxph() and cch() is same, but the lower and upper CI

I've been on vacation and so come late to this interesting discussion. Let me add two minor points. 1. I have run into a lot of statements that "x is required" when dealing with pharma, and in particular wrt NDAs (new drug application). Almost all were false. But I also understand a bit of where they are coming from. An NDA costs millions, with the required trials, and is a

Dear R-users I would like to fit weibull parameters using "Method of moments" in order to provide the inital values of the parameter to de function 'fitdistr' . I don`t have much experience with maths and I don't know how to do it. Can anyone please put me in the rigth direction? Borja [[alternative HTML version deleted]]

Samba mount (from one of our build scripts). We decided to upgrade to RedHat 7.2 (which uses a newer version of Samba -- 2.1.1b IIRC), maybe that fixes the problem. However, I decided to submit this bug report, in the hope that it may help kill some bugs. (Remember -- the only good bug, is a dead bug :)) So, here is the dmesg output: Linux version 2.2.16-22enterprise

Hi, I am trying dovecot-1.1 with dovecot-sieve-1.1. First, dovecot -n do not report about deliver settings. They are: --- protocol lda { postmaster_address = postmaster at parkheights.dyndns.org hostname = parkheights.dyndns.org mail_plugins = cmusieve mail_plugin_dir = /usr/lib64/dovecot11/modules/lda sendmail_path = /usr/lib/sendmail auth_socket_path = /var/run/dovecot11/auth-master