topic Re: Incremental Area Under Curve (iAUC) Calculation in Statistical Procedures

Incremental Area Under Curve (iAUC) Calculation

njdempster — Wed, 30 May 2018 15:19:16 GMT

Hi,

I am unfamiliar with SAS and trying to calculate the incremental area under the curve. I normally use SPSS and have been unable to find syntax to do so using that program. I did, however, find a guide to do this in SAS (attached) that I imagine would be very helpful if I was more familiar with it!

The method I am particularly keen to use is the "positive incremental area under the curve" one. I have downloaded SAS and am managing to successfully calculate the total AUC using the example data and code in attached guide. I am, however, struggling to get the code to work using the code required for the alternative methods such as iAUC

I'd be very grateful if anyone could paste the code as I should be entering it into SAS to determine the iAUC. I have also pasted a sample of data (left column is time in minutes, right column is glucose concentration in response to a standardised meal) that is representative of the data I have for my study:

0	4.746
15	6.688
30	7.053
45	6.953
60	5.483
90	4.654
120	4.532
180	4.455
240	4.393
300	4.295
360	4.621

Any pointers would be much appreciated and apologies if this is very basic.

BW,

Niall

Re: Incremental Area Under Curve (iAUC) Calculation

ballardw — Wed, 30 May 2018 15:56:33 GMT

You would be much better of to post the code you attempted.

And example data in the form of a data step.

A data step would look like this:

data example;
   input variable1 variable2;
datalines;
0  4.746
15 6.688
;
run;

If the code you attempted had errors paste the log result with the code and the error messages into a code box opened using the forum {I} icon. The code box prevents the forum from reformatting text that will corrupt some of the error diagnostics SAS supplies in the log.

Re: Incremental Area Under Curve (iAUC) Calculation

njdempster — Wed, 30 May 2018 19:16:42 GMT

Hi,

I have attached the code that I have pasted from the file, which creates a table for the data but doesn't appear to calculate the iAUC.

Re: Incremental Area Under Curve (iAUC) Calculation

njdempster — Wed, 30 May 2018 19:18:57 GMT

I then tried to modify the macro part of the code (the guide says choose 0, 1 or 2 as baseline depending on what type of AUC you want, I changed "dataset" to "DataFile" and output to "computed" (which is in the guide).

I then get the error that name 1 isn't a valid macro parameter

BW,

Niall

Re: Incremental Area Under Curve (iAUC) Calculation

Ksharp — Thu, 31 May 2018 13:45:50 GMT

I remembered @Rick_SAS wrote a blog about calculated AUC of logistic model .

Calling @Rick_SAS