When laboratory tests can mislead even when they appear plausible.

Area of Science:

• Clinical Chemistry
• Diagnostic Accuracy
• Laboratory Medicine

Background:

• Laboratory testing involves pre-analytical, analytical, and post-analytical phases.
• Immunoassays are widely used in vitro diagnostic tests but have inherent error rates.

Purpose of the Study:

• To address analytical phase issues in immunoassay testing.
• To present a method for clinicians to identify potentially erroneous immunoassay results.

Main Methods:

• Review of immunoassay technology and its analytical phase limitations.
• Application of Bayesian inference principles (non-mathematical) to interpret diagnostic results.

Main Results:

• Immunoassays can yield inaccurate and misleading results, leading to misinterpretation.
• False positive rates are higher in low disease prevalence; false negatives increase with higher prevalence.
• A Bayesian approach aids in discerning plausible but erroneous results.

Conclusions:

• Clinicians can use a Bayesian framework to critically evaluate immunoassay results.
• Follow-up testing is crucial to confirm diagnostic reliability when results are questionable.