Background: This study compared the effectiveness of using the Early Detection of Alcohol Consumption (EDAC) test versus gamma-glutamyltransferase (GGT) to screen for heavy drinking in the general population. Alcohol use was recorded by personal interview; heavy drinking was defined as males drinking 2.5 ounces of alcohol (5 drinks) per day and females drinking 2 ounces (4 drinks) of alcohol daily.
Material/Methods: The population analyzed consisted of 1,022 males (618 heavy drinkers and 404 light drinkers) and 583 females (203 heavy drinkers and 380 light drinkers). The EDAC used 27 routine laboratory tests; a P-positive value >50% was indicative of heavy drinking. The GGT test used a cutoff of 85U/L for males and 65U/L for females.
Results: The results showed that 30% of males reporting heavy drinking tested GGT positive compared to 65% who tested EDAC positive. Specificity was 92% for GGT and 89% for EDAC. Assuming 30% heavy drinking in this population, Positive Predictive Value (PPV) for GGT was 0.62 compared to 0.71 for EDAC. For females, the results showed that 23% of those reporting heavy drinking tested GGT positive compared to 34% who tested EDAC positive. Specificity was 94% for GGT and 98% for the EDAC. PPV for GGT was 0.62 compared to 0.88 for EDAC.
Conclusions: The EDAC test identified twice as many males and 50% more female drinkers than GGT. With higher PPV, the EDAC is a better approach to screen for heavy drinking in both males and females.

Keywords: Alcohol Drinking - blood, Biological Markers, ROC Curve, Time Factors, gamma-Glutamyltransferase - metabolism