Detecting Alcohol Use with EtG and EtS
State physicians health programs began using EtG, a minor non-oxidative metabolite of alcohol, to test for alcohol consumption in 2003. This followed a large study of alcoholics in a psychiatric facility in Germany in which EtG was found to be a more sensitive and accurate test than urine alcohol. One of the physicians involved in the study, Dr. Gregory Skipper, had been looking for a more reliable method of documenting alcohol abstinence. Dr. Skipper oversees Alabama’s Physician Health Program. The Federation of State Physician Health Programs estimates that over 9,000 physicians are currently in monitoring in the United States. Having a reliable method of testing for abstinence was essential for the safe return to practice of recovering physicians. “The long-term success rate for physicians with alcohol and drug problems is very high and few cases of harm to patients have ever been documented.” 1
Once laboratories started to make the test available, additional studies also reported its efficacy in monitoring health professionals. Use of EtG testing then became common among physician health programs.
Prior to the discovery of EtG as a more accurate indicator, blood and urine tests were utilized. Their use however had certain deficiencies, principally among them was that an acceptable time spectrum for detection was lacking. Additionally, they lacked sensitivity and specificity. In contrast, a few hours after alcohol consumption, EtG in urine will be positive and will be present for about 4 days.
However, EtG was not a perfect indicator. The amount of alcohol consumption based on the EtG reading was not clear. There were other variables that could interfere such as enzyme production, and urine concentration. EtG was also vulnerable to bacteria.
EtG is a screening test only. It it not proof. If the individual has come into contact with alcohol from other sources, such as hand sanitizers, the test may be positive. Physician health programs often warn participants to avoid incidental exposure.
In time, it was discovered that EtS, another minor metabolite of alcohol, was not as subject to these issues. For example, EtS could not be degraded in urine due to certain bacteria. EtS, has proven to be a superior marker in that it is more sensitive and specific. Some authors recommend that both tests be used when possible to improve sensitivity.
MPHP uses both measures in tandem in tracking our physician participants for maximum accuracy. Utilizing these markers makes it harder for recovering physicians to cheat, and thus is a better deterrent. If they do decide to drink, “earlier detection will help prevent harm to patients, appropriate referrals can be made and help may be sought for these individuals. 2
1 J.H. Shore, “The Oregon Experience with Impaired Physicians,” JAMA, 1987:257(21), 2931-34. G. Skipper, “Treating the Chemically Dependent Health Professional,” Journal of Addictive Diseases (1997); 16(3), 67-74.
2 G. Skipper, W. Wienmann, F. M. Wurst, Journal of Medical Licensure and Discipline, Vol 90, Number 2, 2004, 14-17. __________