11-14-2024
OsoGris
SAS Employee
Member since
06-23-2011
- 82 Posts
- 1 Likes Given
- 21 Solutions
- 40 Likes Received
About
I work at SAS Institute in Technical Support of our Advanced Analytics procedures; erstwhile known as "STAT" Tech Support but this encompasses areas of BASE/SAS, SAS/STAT, SAS/ETS, SAS/QC, SAS/OR, etc.
I support the survival analysis procedures in SAS and some of the advanced regression procedures (among others).
-
Latest posts by OsoGris
Subject Views Posted 833 11-14-2024 06:12 AM 1673 11-08-2024 10:13 AM 868 05-09-2024 09:56 AM 1946 01-11-2024 12:14 PM 865 12-22-2023 11:50 AM 970 12-13-2023 12:25 PM 1240 12-11-2023 10:52 AM 803 12-11-2023 06:26 AM 2839 11-30-2023 09:50 AM 1523 11-07-2023 01:26 AM -
Activity Feed for OsoGris
- Got a Like for Re: How to compute survival probabilities from PROC PHREG fitted model?. 11-14-2024 07:41 AM
- Got a Like for Re: How to compute survival probabilities from PROC PHREG fitted model?. 11-14-2024 06:30 AM
- Got a Like for Re: How to compute survival probabilities from PROC PHREG fitted model?. 11-14-2024 06:18 AM
- Posted Re: How to compute survival probabilities from PROC PHREG fitted model? on Statistical Procedures. 11-14-2024 06:12 AM
- Posted Re: How to plot cumulative incidence with number at risk from survival analysis with competing risk on Statistical Procedures. 11-08-2024 10:13 AM
- Posted Re: The Weibull accelerated failure time model parameters estimated but how to use them for predicti on Statistical Procedures. 05-09-2024 09:56 AM
- Got a Like for Re: Creating adjusted survival plots using PROC SURVEYPHREG?. 01-18-2024 01:06 PM
- Got a Like for Re: Proc Phreg programming statement to create Time-Varying Covariates. 01-17-2024 10:19 AM
- Posted Re: Proc Phreg programming statement to create Time-Varying Covariates on Statistical Procedures. 01-11-2024 12:14 PM
- Posted Re: Propensity Match in 1:1:1 fashion on Statistical Procedures. 12-22-2023 11:50 AM
- Got a Like for Re: Strange result of Proc lifetest in one strata. 12-14-2023 01:15 PM
- Got a Like for Re: Strange result of Proc lifetest in one strata. 12-14-2023 12:06 AM
- Posted Re: Strange result of Proc lifetest in one strata on Statistical Procedures. 12-13-2023 12:25 PM
- Got a Like for Re: PROC PHREG with IPTW weighted cohort: robust standard error. 12-11-2023 11:43 AM
- Posted Re: How to generate compact letter display from multiple comparisons in PROC LIFETEST? on Statistical Procedures. 12-11-2023 10:52 AM
- Posted Re: PROC PHREG with IPTW weighted cohort: robust standard error on Statistical Procedures. 12-11-2023 06:26 AM
- Got a Like for Re: Interaction term in the PHREG procedure. 12-05-2023 03:26 AM
- Posted Re: Interaction term in the PHREG procedure on Statistical Procedures. 11-30-2023 09:50 AM
- Got a Like for Re: Including log rank test with proc phreg. 11-10-2023 04:36 PM
- Posted Re: Including log rank test with proc phreg on Statistical Procedures. 11-07-2023 01:26 AM
-
Posts I Liked
Subject Likes Author Latest Post 1 -
My Liked Posts
Subject Likes Posted 3 11-14-2024 06:12 AM 1 03-18-2021 05:53 AM 1 01-11-2024 12:14 PM 3 12-13-2023 12:25 PM 1 12-11-2023 06:26 AM
07-08-2022
11:56 AM
1 Like
Sometimes using WEIGHT=1 for all observations can produce an error. I would try the FREQ statement.
... View more
07-01-2022
02:34 PM
2 Likes
My latest discussion on this matter with the PHREG developer revealed the following sentiments: "Currently PROC PHREG does not estimate the survival function when there are time-dependent covariates. It is a bit controversial whether it is doable (for example, Fisher and Lin (1999)). My feeling is that it is doable in some situations (for example when all td-covariates are external). Such an implementation will require new syntax to input a profile (trajectory over time) for each time-dependent covariate. In the meantime, I will discuss ideas with my colleagues and our research into this topic is ongoing. If you have any references to share with us, by all means, please do so." I'm sorry to have to give you such bad news but there isn't really a way to plot survival curves for time-dependent covariates.
... View more
07-01-2022
02:32 PM
1 Like
My latest discussion on this matter with the PHREG developer revealed the following sentiments: "Currently PROC PHREG does not estimate the survival function when there are time-dependent covariates. It is a bit controversial whether it is doable (for example, Fisher and Lin (1999)). My feeling is that it is doable in some situations (for example when all td-covariates are external). Such an implementation will require new syntax to input a profile (trajectory over time) for each time-dependent covariate. In the meantime, I will discuss ideas with my colleagues and our research into this topic is ongoing. If you have any references to share with us, by all means, please do so." I'm sorry to have to give you such bad news but there isn't really a way to plot survival curves for time-dependent covariates.
... View more
06-21-2022
04:06 AM
1 Like
You don't get HR for interaction terms in the ParameterEstimates table. You need to use a HAZARDRATIO statement with the AT= option to specify the level of the interacting variable. Also, the COVS(AGGREGATE) does nothing unless you have an ID statement to identify the clusters. proc phreg data = CANIMPT.capstoneclean covs(aggregate) covm; class ironcat vitccat; model fup_t1d*case_t1d(0) = ironcat ironcat *vitccat /ties=discrete risklimits covb; hazardratio "iron unadjusted" ironcat / diff=ref cl=wald; title 'Ironcat consumption and T1D progression'; run; You will also need the PLOTS= option on the PROC PHREG statement in conjunction with the BASELINE statement in the code. See Example 8 Survival Curves in the PHREG documentation for the basics.
... View more
05-25-2022
01:30 PM
Your syntax looks OK to me but with only 2 observations per strata I'm not very surprised you are not getting the Quartiles to be computed. For this to happen the survival curve has to drop below the points of S(t) = .75, .50 and .25 for the first, second and third quartiles respectively.
... View more
05-18-2022
07:19 AM
You can use the TEST statement to test for the association of covariates with survival time. However, you cannot do a KM analysis or curves that take the covariates into account. See Example 1 in the LIFETEST documentation for a discussion of the TEST statement and it's results.
... View more
03-29-2022
04:37 AM
See Example 89.5 Conditional Logistic Regression for m:n Matching<> in the PHREG documentation.
... View more
03-03-2022
04:18 AM
1 Like
Linear limits can sometimes go outside the interval (0,1). The CONFTYPE=loglog generally gives better coverage than linear limits and has been the default for a long time. It is not related to sample size.
... View more
02-09-2022
01:29 PM
I think you want a "Failure plot" where Failure = 1 - Survival. Your code didn't show any plots option but you can use syntax like PLOTS=S(FAILURE) to get a failure plot that is the reverse of a survival plot.
... View more
02-03-2022
01:51 PM
3 Likes
The pointwise confidence limits for the survival function are in the OUTSURV= dataset. This is an option on the PROC LIFETEST statement.
... View more
01-26-2022
03:09 PM
Since you have no BASELINE statement or COVARIATES= data set you have only one set of covariates being plotted by default. This is the reference level of the CLASS variables and the means of any continuous covariates. As such, you might want to try the OVERLAY=BYROW option which "displays, for each covariate set, a separate plot containing the curves for all the strata." This is according to the PHREG documentation on the OVERLAY option.
... View more
10-18-2021
01:18 PM
1 Like
You have referenced the correct SAS Note regarding the quartile upper confidence limits (quartile UCL). There was a Hot Fix in the SAS Note that applied to SAS9.4 (TS1M6) = SAS/STAT 15.1 and is now a part of SAS9.4 (TS1M7) = SAS/STAT 15.2. Typically, after the fix is applied we see that some of the quartile UCL do not actually exist and are missing in the output. I think your current results are correct.
... View more
09-24-2021
02:12 AM
I checked with the PHREG developer on this and "currently there are no methods to compare FG models in PHREG".
... View more
08-02-2021
01:23 PM
1 Like
I think the reason you need to have race as numeric is you are using it in an interaction. Also, your treatment of the null hypothesis of the PH assumption via the test statement is correct.
... View more
07-30-2021
07:19 AM
You cannot use a parametric model specification with the Cox model and PROC PHREG. So, you can't specify a distribution essentially.
... View more