topic Re: Median Difference in Statistical Procedures

Median Difference

bc — Wed, 11 Aug 2010 22:20:45 GMT

I have computed the change from baselines for subjects in each of 2 groups. I would like to compute the median difference (and confidence interval) between the 2 groups for this change score. What procedure will do this?

Thanks.

Re: Median Difference

Doc_Duke — Thu, 12 Aug 2010 02:27:48 GMT

You can get the median from PROCs MEANS, SUMMARY, or UNIVARIATE, among others. The usual confidence interval for a median is the 25th and 75th percentile.

Search for "Keywords and Formulas" on support.sas.com to get the 9.2 descriptions of where you can get what basic statistics.

Re: Median Difference

mfisher — Mon, 16 Aug 2010 18:30:24 GMT

This paper describes what you need:

http://www.lexjansen.com/pharmasug/2000/Coders/cc01.pdf

Re: Median Difference

SteveDenham — Tue, 17 Aug 2010 12:21:37 GMT

The Hodges Lehmann estimate is available in SAS 9.2 in PROC NPAR1WAY, including exact confidence intervals.

Steve Denham

Re: Median Difference

bc — Wed, 18 Aug 2010 19:40:06 GMT

> This paper describes what you need:
>
> http://www.lexjansen.com/pharmasug/2000/Coders/cc01.pd

Thank you - this is exactly what I was looking for (since I'm still using version 9.1).
-Bruce