Study shows optimal blood biomarker level to detect heavy alcohol use

Key takeaways:

• The recommended cutoff value for phosphatidylethanol — 18.5 ng/mL — had a sensitivity of 83.9% and a specificity of 72.7%.
• Researchers noted that rounding up to 20 ng/mL would be acceptable.

Researchers determined that phosphatidylethanol, or PEth, can accurately assess heavy alcohol consumption at an optimal cutoff value of 18.5 ng/mL.

The blood biomarker, which compared well with ankle monitoring, was tested primarily in white men.

Judith A. Hahn, PhD, MA, a professor of medicine at the University of California, San Francisco, and colleagues noted that the U.S. Preventive Services Task Force recommends screening for heavy alcohol use in primary care settings, but not all patients are asked about their alcohol use in the past year.

“Clinicians may be less likely to screen for alcohol use if they themselves drink regularly or due to discomfort, inadequate training, or judgmental attitudes,” they wrote in JAMA Network Open.

The researchers added that even when clinicians screen for heavy alcohol use, self-reporting can be vulnerable to bias, such as recall or social vulnerability biases.

“Thus, while self-report can provide important information, it is key to develop additional methods to identify heavy alcohol consumption in clinical settings,” they wrote.

Although biomarkers of alcohol like PEth could overcome these screening barriers, Hahn and colleagues pointed out appropriate cutoffs need to be determined.

Hahn and colleagues conducted a 4-week diagnostic study of 64 patients, comparing PEth against the Secure Continuous Remote Alcohol Monitor (SCRAM). The participants, mostly white men with a mean age of about 65 years, were previously enrolled in study investigating the link between alcohol use and atrial fibrillation.

The researchers found that the area under the curve for PEth-detected heavy alcohol consumption vs. heavy alcohol consumption detected by SCRAM was 0.83 (95% CI, 0.72-0.93).

The optimal cutoff for PEth was 18.5 ng/mL, which had a sensitivity of 83.9% (95% CI, 66.3%-94.5%) and a specificity of 72.7% (95% CI, 54.5%-86.7%).

Hahn and colleagues pointed out the finding’s cutoff for heavy alcohol use was close to the previously proposed cutoff of 20 ng/mL for detection of greater than minimal alcohol use, “which is a broader definition than heavy alcohol consumption.”

However, they noted 20 ng/mL in the study’s data had a sensitivity of 80.6% and a specificity of 75.8%, “suggesting rounding up to 20 ng/mL would be acceptable.”

The researchers concluded that although PEth levels above 18.5 ng/mL could be used to detect heavy alcohol consumption in older and middle-aged men who may benefit from intervention, “more work is needed to determine optimal cutoffs in other populations.”