Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: Relative survival - strel

From   Sam Leary <>
Subject   st: Relative survival - strel
Date   Thu, 06 Oct 2011 11:07:26 +0100

Dear all, I am a bit of a novice at survival analysis, but am trying to calculate relative survival using strel. My variables are

death_5y = 1 if died by 5 years after diagnosis, 0 if still alive at 5 years
age_diag = age at diagnosis (years)
age_death = age at death or 5 years, whichever came first (years)

I have downloaded a lifetable which has the following variables:
country calendar_year sex age rate
and I have only kept the data for the calendar year relating to the start date of my audit. I have also sorted this file by age then sex.

So I have used the following commands to calculate the crude and relative survival at 5 years after diagnosis:

stset age_death, failure(death_5y) origin(age_diag)
strel 0 5 using "ltab_s1",mergeby(sex)

My question is, as there are 257 deaths out of a total of 468, why is the crude survival percentage 41.86 using strel, rather than (468-257)/468 = 45.1?

Many thanks,


Dr Sam Leary
Senior Lecturer in Statistics

Working hours:
Monday, Tuesday and Thursday
7.30am - 2.30pm

Lifecourse Epidemiology and Population Oral Health Research Group
Department of Oral and Dental Sciences
Bristol Dental School
Lower Maudlin Street
Tel 0117 342 3264
Fax 0117 342 4443
*   For searches and help try:

© Copyright 1996–2015 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index