Tagged Questions
1
vote
0answers
17 views
Survival analysis in SAS-is there a way to include a random effect with interval censored data?
I'm trying to use some form of survival analysis (e.g. accelerated failure time or proportional hazards) to study seed germination time. My data is interval censored (also called "grouped-time") and ...
0
votes
0answers
47 views
What is the Survival Function using SAS LIFEREG with lognormal distribution?
I am trying to plot the survival curve using output from PROC LIFEREG with a lognormal distribution. Is my formula for the survival function (prob[i], where i is time) correct?
Below is my SAS code. ...
0
votes
0answers
102 views
Interpretation of sas output of survival Frailty model using Proc NLMIXED
I am new to the site, I am trying to fit a Weibull gamma frailty model in SAS for multiple event times per subject, using proc nlmixed procedure. Please how do I ...
3
votes
1answer
317 views
PROC NLMIXED and PROC LIFEREG not arriving at the same answer for Log-normal survival function
Related question
I have a project where, despite being able to implement some parametric models in LIFEREG, it is somewhat more convenient to do it in NLMIXED. Verifying that this technique works, I ...
5
votes
1answer
329 views
R packages (or SAS code) to produce two simultaneous Kaplan-Meier curves?
There's a way to do survival analysis of two (or more I suppose) mutually exclusive competing risks as a mixture of two different survival curves. Something like what you see in A.C. Ghani et al. ...
4
votes
0answers
132 views
Specifying the linear predictor, survival function and PDF of a log-normal survival distribution
Continuing on my exploration of the log-normal distribution, I'm working on reimplementing some code originally written for a Weibull/Exponential model for a log-normal model. Among the things it does ...
1
vote
1answer
273 views
Oddity in simulating Weibull survival times
Based on this guide to simulating survival times in SAS and R, I used the following code to generate two survival functions:
...
2
votes
1answer
351 views
Floating Point Overflow while computing the Kaplan-Meier estimator in SAS
I try to estimate survival curves based on a Kaplan-Meier estimator using proc lifetest. However, SAS outputs an error message which I do not manage to circumvent. ...
0
votes
1answer
192 views
How do you plot survival functions for specific values of covariates in SAS?
Suppose I do the following:
proc phreg data = new;
model time*censor(0) = x y;
run;
Also suppose $x$ is a binary variable and $y$ is a ...
0
votes
1answer
399 views
SAS Code for Survival Analysis
In PROC PHREG, how do you set a continuous variable at a certain value as the reference level? For example, suppose x = 3.5, 3.6, 4.3, 5.4 and we want x = 6 to be the reference level. How would you do ...
