Article on Urine Drug Testing, very helpful

Hi, here is a link to a scholarly article that is very helpful in trying to figure out what the "numbers" mean in a urine drug screen.
http://cdn.intechopen.com/pdfs-wm/28113.pdf

I hope this is helpful to some of you who may have ever been/ or will be in the same situation that I was in recently.

To correctly reference this work, here is the info:

Amadeo Pesce, Cameron West, Kathy Egan-City and William Clarke (2002), Diagnostic Accuracy and Interpretation of Urine Drug Testing for Pain Patients: An Evidence-Based Approach, Toxicity and Drug Testing, Prof. Bill Acree (Ed.), ISBN: 978-953-51-0004-1, InTech, Available from:
http://www.intechopen.com/books/toxicity-and-drug-testing/urine-drug-testing-in-pain-patients