Phosphatidylethanol (PEth) testing is a reliable method to help create a picture of alcohol consumption.
Doctors commonly ask patients how much alcohol they drink. Usually Doctors just take the patient’s word for it, and treat them medically based on the claims.
Liver organ donations are a limited resource and are gifted based on need (eg the MELD score) and also the probability of success. Success includes the transplant surgery and the subsequent quality of the donated liver and recipient’s life. Drinking alcohol with a damaged or transplanted liver harms the liver and that success. So doctors are not going to take your word for it: you are going to have to prove you are sober now and will be sober going forward after the transplant.
Medically sober is complete abstinence from alcohol. There are obvious sources of alcohol like wine, beer, or a martini. But there are medically significant amounts of alcohol in foods (especially sauces), cough medications, and mouthwash. Medically sober is complete avoidance of alcohol in any form, and doctors take your blood not your word to prove it.
The gold standard of alcohol consumption testing is the PEth test. This blood test can detect alcohol consumption over the last four weeks by the presence of phosphatidylethanol in your bloodstream. This phosphatidylethanol is produced due to consumption of ethanol (alcohol) and stays present for much longer than the alcohol and is detectable at the nanogram level. That is one-billionth of a gram. A tiny amount.
Even though the PEth test is at the nanogram level, they do realize that there is some error range in the test. For Stanford the values they use are:
To be Medically Sober you want to get a 'Not detected'. That is the only one where there is basically "no argument". If you get 'Light' then you may need to investigate and explain why you have consumed alcohol that got you that 'Light' value. Depending on your medical program that may be fine. I only have anectdotal information: all my PEth results were negative as I had been completely (medically) sober for half a year before going into Stanford ER.
There are alternative to PEth tests including EtG (Ethyl Glucuronide) urine, blood, and hair tests. Sporadically I had straight 'Ethanol' tests, but I was unable to produce urine due to kidney failure, so I never had experience with these tests if they were ordered.
Being 'Sober Now' for six months is commonly required to get on a transplant list, but the doctors also care about you being sober with the new (reused) liver. They want the liver and you to have a good life together, so you must be sober for it too. Six months of sobriety provides a 60% chance of not relapsing statistically. Those are not good-enough odds to be given a new liver.
On top of being sober, you need to prove that you are committed to being sober. Variations of this commitment include:
Of the above, the last two seem to vary a lot among medical programs or initial patient sobriety state. I was not required to do an IOP, but was required to prove regular sobriety support attendance. And that commitment of attendance continues for years after the transplant. It is possible that some programs don't have the sobriety support requirement, and other programs seem to require IOP attendance.
Note also that the 'Sober Now' tests will likely continue sporadically during the period you are on the transplant waiting list. They may trust your word more as time passes, but they don't trust it completely.
I believe a major missing piece from the sobriety support system described above is regular medical peer support for pre-transplant and post-transplant patients. Some hospitals have monthly support meetings, but these have issues with infrequency and 'supervisor' presence. Medical support from LifeRing's Liver Spot and other programs can make keeping sober easier because people understand both sobriety issues and the stresses of the medical illness that could cause lapses of sobriety.
