All Questions
26
questions
0
votes
0
answers
10
views
Recurrent event model - time to multiple medication discontinuations
I am using the following recurrent event model (counting process style input) to plot cumulative mean frequency of multiple medication initiations. Just like patients in the study can initiate ...
- 1
0
votes
0
answers
28
views
Marginal structural model using PROC PHREG
I would like to fit a marginal structural model to account for treatment switching during follow-up.
I found a great paper on how to do this in R: https://www.sciencedirect.com/science/article/abs/pii/...
- 615
1
vote
0
answers
164
views
How does the "ZPH" option of PROC PHREG in SAS 9.4 works?
As I saw in SAS 9.4 documentation, the "ZPH" option in PROC PHREG statement requests diagnostics based on the weighted Schoenfeld residuals for checking ...
- 123
11
votes
1
answer
585
views
SAS and R produced different results for the same cox ph model on the same data
I have fitted a Cox ph model using both R 4.3.1 and SAS 9.4 with the same data. In SAS, I used Proc phreg, while coxph function ...
- 123
1
vote
1
answer
231
views
In SAS what is the difference of including treatment variable in model and using the strata statement for treatment variable?
Im building a Cox Regression in SAS. My code looks like this:
...
- 77
1
vote
1
answer
370
views
Cox model for different time intervals within follow up time
I have a survival data upto 10 years of followup. I now need to run Cox models for different time horizons like 0-2yr, 2yr-4yrs, 4-6yrs and so on. Is there an easy way to do it in SAS or do I need ...
- 13
1
vote
1
answer
110
views
Reformat data problem for Cox model in SAS
I am relatively new to SAS. Currently I am taking survival analysis course, and I am really stuck on reformatting a data into 'counting process' (start, stop) form for fitting a Cox regression model ...
0
votes
1
answer
297
views
How to create KM curves with time-dependent covariate
Some patient received an treatment as treated group and some did not as control group. In order to consider "immortal time bias", I coded the treatment as a time-dependent covariate. Could ...
0
votes
0
answers
2k
views
Interaction with restricted cubic spline - comparison between SAS and R
When performing the same cox-regression in SAS and i R (including and interaction with a 3 knot restricted cubic spline), I receive different parameter estimates (i.e on age_spline 2). In my example ...
- 1
0
votes
0
answers
413
views
How to estimate the n-year Hazard Ratio from PROC PHREG
Dear SAS users in the CV community:
I am using the sample data publicly available at:
https://stats.idre.ucla.edu/wp-content/uploads/2016/02/whas500.sas7bdat
The tutorial is found here along with a ...
- 101
2
votes
2
answers
3k
views
Continuous vs Categorical covariate of interest in Cox Regression
I will use aliases throughout to explain my results in brief and a few questions that have propped up in the process.
Suppose I'm interested in the association of baseline measurement of blood ...
- 367
0
votes
1
answer
1k
views
SAS Proc lifereg phreg and lifetest - survival plot
I have to draw a survival probability plot with three different surviuval estimates using the phreg, lifereg and the lifetest procedure with sas for make a confrontation
the models:
...
- 75
1
vote
1
answer
893
views
Survival analysis - time-dependent covariate with left truncation
I have some data on patients receiving pancreas transplants. Some of these patients have a procedure done post-transplant called enteric conversion, and I am looking at the effect of this conversion ...
- 297
2
votes
0
answers
39
views
Cox-Hazard Ratio differences in Software suits; Manual calculation
Working in clinical research my task is to calculate the Hazard ratio, better to check the calculations of someone else. This first calculation was based on ARM=(3 different treatments) with only t=(...
- 97
1
vote
1
answer
1k
views
Cox Proportional Hazards Model with Time-Dependent Covariate and Late Entries in SAS [closed]
I am trying to fit a model in SAS that allows for both late entries (i.e. left truncation) and a time*covariate interaction. I can fit both separately:
Late entries:
...
- 11