st: collapsing data from multiple follow-up visits

[Ashwin Ananthakrishnan <ashwinna@yahoo.com>]

Hi, 

I was wondering if somebody can give me tips on collapsing data points in Stata. 

I have an Excel spreadsheet with several study participants. Each participate has one row with their baseline information (medications). 

At each subsequent visit, the medication information is updated. This is on separate row. The follow up visits are at different time points for different participants and at varying intervals (i.e one person can have a 3 and 6 month follow up, while another can have a follow up visit at 10 months only).

What I would like to do to facilitate analysis is to collapse all data for each participant into one row. All I'm interested in knowing if if they were ever on a specific medication during their follow-up. The "time to new medication use" is not important. 

Is there a way in Stata or Excel to do this without having to manually go through all the follow-up visit rows for each of the 400 or so participants? 

Thanks, 

Ashwin


 


      
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