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Re: st: stsum, stdes... median age


From   "Svend Juul" <SJ@SOCI.AU.DK>
To   <statalist@hsphsun2.harvard.edu>
Subject   Re: st: stsum, stdes... median age
Date   Fri, 16 Mar 2007 10:30:25 +0100

Pascal Sebille wrote:
 
I have a question about the 50th percentiles of survival
time with stsum, stdes...
I want to estimate median age with 2 decimales; ex: 20,32.
But with stsum, stdes... we have just whole age; ex: 20.
------------------------------------------------------

This occurs when the study time is expressed as integers.
The median time tends to be an actually measured time. 
Try to run these commands and see what happens.

   sysuse cancer
   stset studytime , failure(died==1)
   stsum
   replace studytime=studytime+uniform()
   stset studytime , failure(died==1)
   stsum

Hope this explains.

Svend
__________________________________________

Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(Institute of Public Health, Department of Epidemiology)
Vennelyst Boulevard 6
DK-8000  Aarhus C, Denmark
Phone: +45 8942 6090
Home:  +45 8693 7796
Email: sj@soci.au.dk
__________________________________________ 

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