stsum vs stdescribe- which to use?

[Amaranta Losey]

Hi all-
I am getting different median follow up time between stsum and stdescribe. Cohort looking at cancer survival- survival time caluclated between time diagnosed and time failed (either recurred or death or last contact(
I have time in days so I changed it to months by the scale option in stset


. stdescribe

failure _d: recur == 1
analysis time _t: recur/30

|-------------- per subject --------------|
Category total mean min median max
------------------------------------------------------------------------------
no. of subjects 126
no. of records 126 1 1 1 1

(first) entry time 0 0 0 0
(final) exit time 21.20682 .4333333 16.93333 93.33333

subjects with gap 0
time on gap if gap 0
time at risk 3732.4 21.20682 .4333333 16.93333 93.33333

failures 120 .6818182 0 1 1
------------------------------------------------------------------------------



. stsum

failure _d: recur == 1
analysis time _t: recur/30

| incidence no. of |------ Survival time -----|
| time at risk rate subjects 25% 50% 75%
---------+---------------------------------------------------------------------
total | 3732.4 .0321509 176 13.33333 18.66667 26.9


Any clue as to what I am doing wrong to get different output?

Thanks!