missing data items

From: "Paul S. Collier" <p.collier@qub.ac.uk> Subject: missing data items Date: Mon, 11 Sep 2000 15:11:25 +0100 Is there a way in which I can code for missing data relating to a possible covariate? An example would be where I have recorded Serum K for the majority of my subjects and wish to investigate whether or not this influences a p'kinetic parameter. How do I code for the fact that the data item is missing in a few individuals? If I use "0" or "." I assume that NONMEM reads this as a zero value rather than as a missing value. Paul ********************************************** Dr P.S. Collier School of Pharmacy The Queen's University of Belfast 97 Lisburn Road Belfast BT9 7BL N. Ireland, U.K Tel: +44 (0)28 90 272009 FAX: +44 (0)28 90 247794 Email: p.collier@qub.ac.uk http://www.qub.ac.uk/pha/index.html