Hi DrBill (and anyyone else kind enough to provide answer),

My question is about the EtG/EtS ratio relating to common testing cut-off levels. EtS cut-offs are commonly set at 1/4 of the EtG cut-off, but the only study I found regarding this ratio (Hoiseth, Bernard, et al. 2007) seems to indicate a 3/5 cut-off would be more accurate. Am I missing something here?


http://alcalc.oxfordjournals.org/content/43/2/187.full

There is no agreed upon cutoff for either EtG or EtS. I believe that you will find the ratio to vary from one test source to another, arbitrarily chosen and based on no more than the theory that EtS is produced in less quantity than EtG.

If you are interested in a comparison of the elimination profile of the two you could begin with Dresen, etal 2004 (http://dionysus.psych.wisc.edu/lit/articles/DresenS2004a.pdf), who was working with Wurst, who first introduced EtG to the testing market.

The more I learn about this testing the less faith I have in it... thanks very much.