I use the collapse command when dealing with claims data structure much
the way your clinic visit data is.
I would suggest the following syntax:
collapse (sum) clinic, by (patient_id)
Josiane "Josie" Georges
Sr. Planning Analyst
Division of Mental Hygiene
Tel: 212-219-5194
Fax: 212-219-5192
Email: [email protected]
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Shehzad Ali
Sent: Wednesday, April 15, 2009 10:48 AM
To: [email protected]
Cc: [email protected]
Subject: st: simple sum() question
Hi,
I have a simple question about summing across observations. I have 100
patients (variable: patient_id) in the dataset, each had clinic visits
(variable: clinic) and hospital visits (variable: hospital) recorded at
weeks 4, 8, 12 and 16. The dataset is long and hence I have 400
observations (one observation per patient per time point).
I want to sum the clinic visits for each patient (across all 4 visits)
bearing in mind that some patients had less than 4 visits. So
effectively I
want to generate a new variable that will produce the sum of clinic
visits
for each patient.
Any help would be appreciated.
Thank you,
Shehzad
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