PEth blood test detects hazardous alcohol use missed by screening

Primary care professionals screen patients for harmful alcohol use by using questionnaires such as the Alcohol Use Disorders Identification Test (AUDIT) and by asking patients about their typical weekly alcohol consumption. Phosphatidylethanol (PEth) is a blood alcohol biomarker that can provide an alternative approach to identifying hazardous alcohol use in primary care by reflecting alcohol consumption over preceding weeks. Researchers in Sweden used health record data from 2013 to 2023 to examine the alignment between patients' two self-reported measures of alcohol use and PEth tests. Hazardous alcohol use was defined as a PEth level of greater than 210 ng/mL (0.30 µmol/L), an AUDIT score of 8 or higher, and a reported consumption of 10 or more drinks per week. Here's what they found:

• 5.8% of primary care patients who reported below threshold (<8 points) for hazardous alcohol use on the AUDIT questionnaire had hazardous levels of alcohol on their PEth blood biomarker test.

• Estimates of hazardous alcohol use varied substantially, depending on the assessment method. The AUDIT questionnaire flagged the most patients (26.5%) for risky alcohol consumption. The PEth blood biomarker test flagged 15% to 18%. Asking patients how much they drank each week flagged the fewest, at 8.5%. 

• At similar PEth biomarker test result levels, men and patients with higher education or income reported greater weekly alcohol use, while younger patients had higher AUDIT questionnaire scores. 

Why it matters: The study findings show that no single measure captures the full picture of a patient's drinking and support a multimethod approach to alcohol screening in primary care where PEth biomarker tests and self-reports are used as complementary rather than interchangeable tools.