"The present study sought to test the validity of a commercially available uEtG test to detect past day drinking, past day binge drinking, past 3-day drinking, and past 3-day binge drinking in a sample of heavy drinkers. We found that while uEtG was reasonably able to detect past day alcohol use and past day binge drinking, detection of drinking and binge drinking in the past 3 days was poor. These findings were consistent with a recent study examining the utility of uEtG testing among women of childbearing age, which found poor sensitivity to detect light-to-moderate drinking beyond a 12-hour window (Graham et al., 2017). These preliminary results call into question the validity of commercially available urine EtG tests at the manufacturer recommended detection cutoffs as means of validating alcohol abstinence and binge drinking in clinical research. It is important to consider the sensitivity of detection window as the current uEtG was commercially sold to detect alcohol use in the past 80 h, yet was only accurate for detecting past 24 h’ alcohol use. As false positives are common with uEtG tests (Costantino et al., 2006; Wurst et al., 2015), researchers should be aware of the limitations of urinary EtG using the manufacturer recommended detection threshold of 500 ng/ml and should not rely on commercial uEtG alone as verification of past alcohol use, particularly when using conservative detection thresholds. Breath alcohol concentrations (BrAC) should be used in conjunction with physiological biomarkers and self-report in order to accurately capture recent alcohol intake."
Grodin, Erica N et al. “Sensitivity and specificity of a commercial urinary ethyl glucuronide (ETG) test in heavy drinkers.” Addictive behaviors reports vol. 11 100249. 17 Jan. 2020, doi:10.1016/j.abrep.2020.100249