Quantifying Alcohol Consumption in the General Population by Analysing Phosphatidylethanol Concentrations in Whole Blood: Results from 24,574 Subjects Included in the HUNT4 Study

A study of the association between PEth in blood and alcohol consumption in 24,574 subjects in the HUNT4 study. A cut-off of 0.03-0.06 mu mol/l (or 20-40 ng/ml) detects alcohol consumption above 1-2 units/day, with a threshold of three units per day a cut-off of 0.1 mu mol/l (70 ng/ml) is appropriate. Aims To evaluate the association between self-reported alcohol consumption and phosphatidylethanol (PEth) concentrations in blood in a large general population study, and discuss optimal cut-off PEth concentrations for defined levels of alcohol consumption. Methods Population based, longitudinal cohort study including 24,574 adults from The Trondelag Health Study 4 (HUNT4) conducted in Trondelag County, Norway. Data included PEth concentration, self-reported alcohol consumption and CAGE score. Results PEth levels in whole blood increased with the number of alcohol units consumed, the frequency of alcohol consumption, the frequency of binge drinking and the CAGE score (lifetime, i.e. 'have you ever'). The cut-off concentrations with highest combined sensitivity and specificity were 0.057 mu mol/l (40 ng/ml) for identification of those consuming >1 alcohol unit per day (sensitivity 86%, specificity 76%), 0.087 mu mol/l (61 ng/ml) for consuming >2 units per day (sensitivity 87%, specificity 81%) and 0.122 mu mol/l (86 ng/ml) for consuming >3 alcohol units per day (sensitivity 80%, specificity 86%). By defining a CAGE score >= 2 as potentially harmful consumption, a cut-off of 0.100 mu mol/l (70 ng/ml) identified 52% of all those subjects. Conclusions Cut-off limits of PEth concentrations should take into account the indication for sampling. Using cut-offs for the PEth concentrations of about 0.05 mu mol/l (35 ng/ml) and 0.08 mu mol/l (56 ng/ml) would identify about 90% of the subjects consuming more than 1 and 2 alcohol units per day, respectively. Concentrations above these cut-offs should lead to a more detailed interview related to alcohol use.

Automated summary

This study examined the association between PEth in blood and alcohol consumption in 24,574 subjects in the HUNT4 study. The study found that a cut-off of 0.03-0.06 mu mol/l (or 20-40 ng/ml) can detect alcohol consumption above 1-2 units/day, and a cut-off of 0.1 mu mol/l (70 ng/ml) is appropriate for a threshold of three units per day. The results provide optimal cut-off PEth concentrations for defined levels of alcohol consumption.