The Curious Incident of the False Lipemia Index Alert

Laboratorians utilize the HIL index to detect potential analytical interference from hemolysis, icterus, and lipemia (HIL) in serum and plasma samples. Thus, implicit to an HIL index alert is the presence of significant hemolysis, icterus, or lipemia in a sample. Indeed, in our experience, lipemia index alerts are accurate 99.9% of the time. But what does it mean when a lipemia alert flags a specimen with no visible evidence of lipemia or turbidity?