Effort During Ethanol Breath Testing Impacts Correlation with Serum Ethanol Concentration.

Area of Science:

• Clinical Chemistry
• Toxicology
• Emergency Medicine

Background:

• Serum ethanol testing is the gold standard for quantifying intoxication.
• Breath testing offers a faster, less invasive, and more cost-effective alternative.
• The impact of perceived effort on breath ethanol test accuracy is not well understood.

Purpose of the Study:

• To investigate whether perceived "poor" effort during breath ethanol testing affects its correlation with serum ethanol concentration.
• To compare the accuracy of breath ethanol tests with normal versus poor perceived effort.

Main Methods:

• Retrospective analysis of 480 patients with both breath and serum ethanol tests within 60 minutes.
• Breath test effort was categorized as "normal" or "poor" by the administrator.
• Descriptive and correlation analyses were performed.

Main Results:

• Patients with normal effort (n=245) showed a strong correlation (r=0.92) between breath and serum ethanol.
• Patients with poor effort (n=235) exhibited a weaker correlation (r=0.63).
• Poor effort was associated with higher reported breath ethanol levels and greater variability between breath and serum values.

Conclusions:

• Perceived effort during breath ethanol testing is a critical factor influencing its correlation with serum ethanol levels.
• Poor breath effort significantly reduces the reliability of breath ethanol test results.
• Physicians should exercise caution when interpreting breathalyzer results from patients with perceived poor effort, especially when clinical decisions depend on accuracy.