topic Number of Patients with Particular Diagnosis in SAS Programming

Number of Patients with Particular Diagnosis

DMMD — Sat, 15 Oct 2016 22:08:30 GMT

Hello,

I have a dataset of patients with up to ten different diagnoses (over ten different columns). Each patient, additionally, may have more than one occurrence.

How do I program SAS to count the number of patients (unique IDs) with a particular set of diagnoses (i.e. diagnosis 1 or diagnosis 2 or diagnosis 3)? I do not want a frequency count of diagnoses as one patient could return multiple times for the same diagnoses.

Thanks!

Re: Number of Patients with Particular Diagnosis

Reeza — Sat, 15 Oct 2016 22:27:19 GMT

Depends a bit. A usual recommendation is to flip your data from wide to long and then do a double proc freq or SQL distinct to get the number of unique people, and use a WHERE clause or filter your diagnosis.

Another option is is to create a flag for the diagnosis and loop through all the diagnoses and set the flag to 1 if the diagnosis is found.

Then you do a distinct count with a filter on the flag value.

A diagnosis usually isn't a single code, case definitions vary and both methods are equivalent.

If you need to work with multiple diagnoses the first method is easier to extend.

Re: Number of Patients with Particular Diagnosis

Reeza — Sat, 15 Oct 2016 22:28:09 GMT

You've posted this in data mining are you using SAS EM?

Re: Number of Patients with Particular Diagnosis

DMMD — Sat, 15 Oct 2016 22:33:48 GMT

Thanks, Reeza. I will try the first option and keep you updated.

I have SAS 9.4 and SAS Enterprise Guide 7.1. Should my post be in a different discussion board?

Re: Number of Patients with Particular Diagnosis

DMMD — Sat, 15 Oct 2016 22:38:05 GMT

Hi Reeza,

Do you recommend using the methos described in the following link to transform the data?

http://www2.sas.com/proceedings/sugi24/Advtutor/p48-24.pdf

Thanks!

Re: Number of Patients with Particular Diagnosis

Reeza — Sat, 15 Oct 2016 23:00:49 GMT

I prefer proc transpose myself. More dynamic.

Yes, probably in Base SAS, I'll move it.

Re: Number of Patients with Particular Diagnosis

DMMD — Sat, 15 Oct 2016 23:19:57 GMT

I'll give that a shot. Thank you!

Re: Number of Patients with Particular Diagnosis

DMMD — Tue, 18 Oct 2016 23:53:02 GMT

Hi Reeza,

I tried to do proc transpose. My data has over 3 million observations and many columns. There are ten separate columns for diagnoses alone.

After running for two hours, I was unable to open the transposed file due to memory issues (not sure what that really means as everything else opens okay).

Re: Number of Patients with Particular Diagnosis

Reeza — Wed, 19 Oct 2016 03:10:23 GMT

Then I suggest a datastep to transpose instead. Not all records have 10 diagnoses, many will be empty, correct?

3 milllion x10 diagnoses - 30 million. Not a small amount but shouldn't cause SAS to crash...