Hello, Did you finally find a solution to this warning? ... View more

Check this: https://communities.sas.com/t5/Statistical-Procedures/Estimating-the-cumulative-rate-and-CI-at-a-certain-time-point/td-p/237049 And there is an Chinese article: https://html.rhhz.net/zhlxbx/201502019.htm ... View more

Thank you very much. LinusH ... View more

The STDDEV= option in the COXREG statement is the assumed standard deviation of the predictor being tested---that is, your best guess of the true standard deviation of this predictor's sampling distribution under the same conditions as expected in the study you're planning. This isn't the same as the standard error of a coefficient estimate, just a simple property of the predictor variable itself as it would be sampled (or perhaps taking on values that you control yourself) in your planned study.   I'd also like to point out that the original question in this thread didn't specify what kind of data analysis is being planned, and it could just as easily pertain to the TWOSAMPLESURVIVAL statement in PROC POWER if you're planning a logrank test rather than a Cox proportional hazards regression. These are two scenarios in which PROC POWER supports the calculation of power for a survival analysis given alpha, hazard ratio, and number of events. ... View more

If the specification you received request summary statistics for time-to-even data such as median survival time, confidence intervals, and 25th – 75th percentiles, you still need to use the LIFETEST procedure and you can use the NOTEST option to skip the inappropriate statistical test. For example, the following codes will not issue the warning message because it does not perform the inappropriate statistical test, but it will still give you the summary statistics. ods output Quartiles=quartiles; proc lifetest data=adtte method=KM alpha=0.05; by subgroup; time AVAL*CNSR(1); strata trt01pn/notest; run; ... View more

Thank you so much for the explanation. It makes sense.  ... View more

Thank you very much, Maguiremg and Tom! I learned from both of you. very nice ideas. ... View more

Thank you KurtBremser and Amir. Your suggestions both work.    ... View more

Thank you Tom.  I found I also have SAS 9.4 (Unicode support) and there is no error with it.    ... View more

@fengyuwuzu wrote: I am not sure if the data need to meet both condition to apply this explanation.   The upper confidence limit for a quartile q p  in PROC LIFETEST is incorrect if these conditions are met: an event is observed at the largest time the largest event time is also the first time the survival estimate drops below (1-p) for the 100pth percentile point, given the pointwise upper bounds for the survival estimate have not dropped below (1-p) at previous times My understanding is that both "these conditions" must be met. (The first criterion alone would also seem to me too weak a condition for SAS to produce "incorrect" results from version 9.2 until 9.4 TS1M6, i.e., over many years.) Moreover, I suspect that the two conditions are only necessary conditions for the error to occur: If I'm not mistaken, the almost trivial example of just two survival times t1=1, t2=2, both uncensored, meets both conditions for p=0.75 and yet the upper confidence limit (=2) for that quartile, as obtained with SAS 9.4TS1M5 (SAS/STAT 14.3) using conftype=linear, matches what I get from the formula in the documentation. ... View more