Interferences, a neglected error source for clinical assays

Abstract

In clinical assays, interfering substances can cause large errors, which in turn can result in severe patient harm. Yet, perhaps because such errors are rare, not much attention is devoted to interferences. This is evident in specifications, which often focus on most, but not all of the results. Methods such as total error analysis, six sigma, and measurement uncertainty intervals are all useful but fail to properly account for interferences, and the Clinical Laboratory Standards Institute standard on interferences has misleading reporting advice. Suggestions are given to improve specifications, protocols, analyses, and reporting methods.