Table 2.

Examples of MIMIC-II tests that were mapped as ambiguous but likely matches.

MIMIC-II test name/specimen type	Mapping issue	Supplemental data	Mapped to LOINC code	LOINC test name	Comments
ANTI-MC/BLOOD	Ambiguous name	Discharge summary text: “She had antibodies sent for acetylcholine receptors and thyroid antibodies which were still pending at the time of discharge” Mayo website[22]: Microsomal antibody = thyroperoxidase antibody	32042-4	Thyroperoxidase Ab [Presence] in Serum
AM BIUR/URINE	Ambiguous name	ARUP website [21]: urate crystals are birefringent Sample values: none, few, mod, many	12454-5	Urate crystals amorphous [Presence] in Urine sediment by Light microscopy	Information from ARUP helped define am bi
PG/OTHER BODY FLUID	Uncertain body fluid	Patient notes: specimen was from amniotic fluid	48785-0	Prostaglandin D2 [Mass/volume] in Body fluid	We did not map to a specific amniotic fluid code because the local MIMIC-II code could potentially be used for different body fluids for different patients.
FREE TEST/BLOOD	Multiple units of measure	Units of measure: ng/dL and pg/mL	2991-8	Testosterone Free [Mass/volume] in Serum or Plasma	This LOINC code has both MIMIC-II units of measure specified as potential units.