Hello, everyone
I am practicing COX regression. I see from the SAS support webpage that, after PROC PHREG, we can plot cumulative hazard graphs with the 95% confidence limits. However, I would like to plot the cumulative hazard graphs with the 95% confidence interval. I did not find the option from the webpage to do so.
As you know, 95%CL is much wider than 95%CI. I see some research publications have cumulative hazard graphs with 95%CI.
I would like to hear your ideas, thanks.
Partial code:
proc phreg data = DSP2_raw plots(overlay = bygroup) = (survival cumhaz); class v1(ref='0') v2(ref='0') v3(ref='0') v4(ref='0') v5(ref='0'); model TimeEvent*Event(0) = v1 v2 v3 v4 v5 v6 v7 ... vn / rl = wald; baseline covariates = predict; run;
@TomHsiung wrote:
As you know, 95%CL is much wider than 95%CI.
????
Confidence limits are the numbers at the upper and lower end of a confidence interval.
Are you referring to prediction band?
A prediction interval is less certain (hence wider) than a confidence interval. That's because a prediction interval predicts an individual number, whereas a confidence interval is for the mean.
Koen
@TomHsiung wrote:
As you know, 95%CL is much wider than 95%CI.
????
Confidence limits are the numbers at the upper and lower end of a confidence interval.
Are you referring to prediction band?
A prediction interval is less certain (hence wider) than a confidence interval. That's because a prediction interval predicts an individual number, whereas a confidence interval is for the mean.
Koen
@sbxkoenk Hi, pal. Thank you for your reply.
Oh! I thought the CL option in plots(overlay cl) was the prediction interval. Probably, I was misled by chatGPT, I think. I remember chatGPT told me CL (confidence limits) and CI (confidence intervals) were different. At the same time, my data showed a very wide band, which led me to the wrong conclusion.
Thank you for your clarification. Appreciated!
Update:
When plots option, overlay & cl, are used together, no CL bands. It shows CL bands when plots option has only cl.
proc phreg data = cox_raw plots(overlay cl) = cumhaz;
@TomHsiung wrote:
Update:
When plots option, overlay & cl, are used together, no CL bands. It shows CL bands when plots option has only cl.
proc phreg data = cox_raw plots(overlay cl) = cumhaz;
That's not my experience.
I have just submitted :
ods graphics on;
proc phreg data=Myeloma plots(overlay cl)=cumhaz;
model Time*VStatus(0)=LogBUN HGB;
baseline covariates=Inrisks out=Pred1 survival=_all_/rowid=Id;
run;
... and it properly shows everything asked for.
Koen
@sbxkoenk Much appreciate for your additional information. I can see that you do researches about INR, haha.
Below is my codes. I don't know what is wrong. Another thing is that I switched from SAS 9.4 to SAS Viya (update: I have tested these code lines on SAS OnDemand, and no CL bands there on cumhaz graph).
proc phreg data = cox_raw plots(overlay cl) = cumhaz;
class genderC(ref = '0') AF(ref = '0') Hypertension(ref = '0') CHF(ref = '0') akiC(ref = '0')
ddiC(ref = '0') indicationC(ref = '0') CYP2C9code(ref = '0') VKORC1Code(ref = '0') Warfarin_History(ref = '0');
model timeToFirstInrAttain*firstInrAttain(0) = bsa ageY genderC AF Hypertension CHF
serumalb akiC ddiC indicationC CYP2C9code VKORC1code Warfarin_History / rl=wald;
baseline covariates = predict_cox;
run;
Hello,
Also on Viya it's working for me (I am using Viya 4 Stable 2024.06).
What SAS Viya version are you using?
Submit:
%PUT &=sysvlong4;
... to find out. See LOG-screen for the answer.
I cannot spot an error in your code.
You can also contact SAS Technical Support (TS) for this. You can do so via the SAS Customer Service Portal (customer portal).
https://service.sas.com/csm
Koen
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