Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.

# RE: st: stset for grouped data

 From "Dherani, Mukesh" To "statalist@hsphsun2.harvard.edu" Subject RE: st: stset for grouped data Date Thu, 14 Apr 2011 11:39:04 +0100

```Thanks. Yes it is aggregated data. What actually I want to do is to calculate the cumulative incidence rate by country.
Assuming that there is no censoring, and on average each person in a particular age group has same age of onset, can't we calculate incidence rate? We have population by age group hence we may be able to calculate total person years of follow-up.   I may be naive here, I thought if I expanded data based on
expand cases
I will get data for an individual and using above assumptions I may be able to calculate the incidence rate.

thanks again.
m
________________________________________
From: owner-statalist@hsphsun2.harvard.edu [owner-statalist@hsphsun2.harvard.edu] On Behalf Of Joerg Luedicke [joerg.luedicke@gmail.com]
Sent: 13 April 2011 19:18
To: statalist@hsphsun2.harvard.edu
Subject: Re: st: stset for grouped data

On Wed, Apr 13, 2011 at 12:06 PM, Dherani, Mukesh
<M.K.Dherani@liverpool.ac.uk> wrote:
> Dear Stata experts,
> I have grouped data and want to estimate incidence rate each year.  How can I set 'stset' when I don't have individual level data.  Do I need to expand data with certain assumptions?
>
> region year agegp cases population
> 1 1994 0-4 2 5000
> 1 1994 5-9 5 2548
> 1 1994 10-14 6 2547
> 1 1994 15-19 15 7521
> 1 1994 20-24 75 7896
>
What do you mean with "grouped"? Is this some aggregate measure from
individual persons? I guess if you do not have data from those
individual persons, you do not have it. I do not know how this
information would emerge by any form of expanding? You probably need
to check if your groups are a reasonable unit of analysis and then do
the analysis for those groups.

J.

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```