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Re: st: Question about strate and stsplit

From   "Svend Juul" <SJ@SOCI.AU.DK>
To   <>
Subject   Re: st: Question about strate and stsplit
Date   Wed, 10 Aug 2005 11:12:41 +0200

Shige asked:

My questions is: 
1) Is it true that _D (number of deaths) cannot be greater than _Y (time
at risk)? 

The time at risk can be expressed in any unit, from seconds to
centuries, and the numerical value of _Y of course depends on the unit

Imagine 10 persons observed within a time window of one year. All 10
died after 6 months. So _D is 10, and _Y is 5. Had you chosen days as
the time unit, _D would still be 10, but _Y would be 1,825.

So I don't think there is a "problem here"


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

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