Hi,
We have survey data on injury counts and want to calculate annual incidence 
rates at different time points (& 95% CIs) adjusting for clustering.
We have a variable (time) which represents time since injury (1-12 months).
I need to first accumulate the injury counts at each time point and then 
calculate the incidence rates. The data is at individual level.
I tried the following code:
collapse (sum) injury time, by(area)
but could not get the accumulated counts.
I would appreciate some help on this.
Thanks
Candida
-- 
Candida Moshiro
University of Bergen
Center for International Health
Armauer Hansen Building
N-5021 Bergen
Norway.
Tel: +47 5597 4691
Fax: +47 5597 4979 (Specify attn.)
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