How many records for the same persion in a given time period?

[MScEpi]

Hi,

I have a SAS data set with some 2 million records.

The records span a period of 5 years.

Many records are representative of the same person.

Each record has a variable for a service date.

I need to find out how many people have records with more than one service date in a seven day period, as well as how many people have multiple records in a one year period.

How can I do this? Would I use a Do loop command?

thanks!

 

[x11dude]

There are different ways to do it - but I'd say NO to the do loop. I'd create new variables (based on your date field) for yr and wk (and possibly a combo yr-wk depending on if you need it). Then Proc Summary.

 

[sasbuddy]

Simple Data Step can also do
1. Take original dataset worted with PersonID, Service date
2. Take 3 new variables last_serv_dt, wk_tot and yr_tot and reatin those variables
3. Use First. and last. on person ID
4. if service_date - last_serv_dt <7 then wk_tot+1
5. if year(last_serv_dt) eq year(service_date) then yr_tot +1

After this you can get the totals of week and year
that is wk_tot and yr_tot



sasbuddy

http://sites.google.com/site/sasbuddy/