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Hello,
I want to find minimum and maximum for duration of response. Is there a way to get those numbers from PROC LIFETEST procedure. Mean, median and 95% CI are straight forward from the procedure. Should I use Proc means or proc summary instead.
My SAS code :
ods output productlimitestimates = km (keep=stratum trtpn Timelist Survival)
Quartiles =_quartiles (keep=stratum trtpn percent estimate lowerlimit upperlimit percent
where=(percent eq 50))
Means = mean
CensoredSummary =_censorsum;
proc lifetest data=want
method=KM timelist=12 24 outsurv=surv;
time dor*dorcnsr(1); /* dor - duration of response */
strata trt;
run;
Any help is much appreciated. Thank you !!
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Hello @Banoo,
@Banoo wrote:
I want to find minimum and maximum for duration of response. Is there a way to get those numbers from PROC LIFETEST procedure. Mean, median and 95% CI are straight forward from the procedure. Should I use Proc means or proc summary instead.
To be consistent with other quantile estimates (such as the median) using the Kaplan-Meier method -- see the "general formula for estimating the 100pth percentile point" in section Breslow, Fleming-Harrington, and Kaplan-Meier Methods of the PROC LIFETEST documentation and consider the cases p → 0 and p → 1 -- I would use
- for the minimum: the smallest duration ("event time," i.e., excluding censored times)
- for the maximum: the largest duration, unless it is censored, in which case the maximum cannot be estimated (cf. missing quartile estimates if the Kaplan-Meier curve doesn't drop far enough).
So, yes, you can use PROC MEANS or PROC SUMMARY, but taking the censoring flag (your variable dorcnsr) into consideration as described above.
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Hello @Banoo,
@Banoo wrote:
I want to find minimum and maximum for duration of response. Is there a way to get those numbers from PROC LIFETEST procedure. Mean, median and 95% CI are straight forward from the procedure. Should I use Proc means or proc summary instead.
To be consistent with other quantile estimates (such as the median) using the Kaplan-Meier method -- see the "general formula for estimating the 100pth percentile point" in section Breslow, Fleming-Harrington, and Kaplan-Meier Methods of the PROC LIFETEST documentation and consider the cases p → 0 and p → 1 -- I would use
- for the minimum: the smallest duration ("event time," i.e., excluding censored times)
- for the maximum: the largest duration, unless it is censored, in which case the maximum cannot be estimated (cf. missing quartile estimates if the Kaplan-Meier curve doesn't drop far enough).
So, yes, you can use PROC MEANS or PROC SUMMARY, but taking the censoring flag (your variable dorcnsr) into consideration as described above.
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