The Reproducibility of the Early Detection of Alcohol Consumption Test Using Split Samples Analyzed in Different Laboratories

Aims: This study analyzes the reproducibility of the Early Detection of Alcohol Consumption (EDAC) test by sending blood samples obtained from nine volunteers to four different laboratories. It also describes the reproducibility of the EDAC over time by analyzing the results of testing one subject whose blood sample was sent to seven different laboratories over a 10-year period. Methods: The EDAC is a method of interpreting routine laboratory profiles to identify either binge drinking or heavy drinking; the components of the routine panel were chosen based on a best fit predictions model published previously. Results: Overall, the results of the cross-sectional analysis showed that the coefficients of variations (CVs) of the routine tests in the panel were mostly below 16%. Only three analytes (total bilirubin, aspartate aminotransferase and monocytes) showed CVs between 20 and 38%. The differences in the EDAC predictions for these volunteers ranged from 0 to 24%. In the long-term analysis, the variation of the EDAC prediction ranged from 0 to 21% probability of heavy drinking for one subject over time. Thus, mild variations of the EDAC are to be expected when the blood samples are analyzed in different laboratories. However, based on this study, these variations in the prediction of heavy drinking should not exceed > 24% when using the EDAC test. Conclusion: This study supports the standard practice established for similar contemporary alcohol biomarkers stipulating that indications of heavy drinking become evident only when subjects experience changes of > 30% in the probability of heavy drinking over time.