Table 3.

Manufacturer recommended LOINC® codes that do not match LOINC® codes used in medical center pilot sites^a

Site	IVD manufacturer and device name	Pilot site data			Manufacturer data for similar test		Potential reason for mismatch
		LIS test name	LOINC®	Pilot test description	LOINC®	LOINC® long common name
Pilot Site 1	Roche Cobas	Calcium, urine	18488-7	Calcium	17862-4	Calcium [Mass/volume] in Urine	LOINC® is for 24 h urine –the IVD manufacturer/instrument may not be aware
		Cannabinoid screen	70143-3	Cannabinoids	8172-9	Cannabinoids [Presence] in Serum or Plasma by Screen method	Quantitative LOINC® vs qualitative by the manufacturer
		Prolactin, serum	2842-3	Prolactin	20568-2	Prolactin [Mass/volume] in Serum or Plasma by Immunoassay	Methodless LOINC®—still a valid LOINC®, but not as granular as the manufacturer LOINC®
Pilot Site 2	Abbott Architect i2000	Hepatitis C Ab	16128-1	Hepatitis C virus Ab [Presence] in Serum	13955-0	Hepatitis C virus Ab [Presence] in Serum or Plasma by Immunoassay	Methodless LOINC®—still a valid LOINC®, but not as granular as the manufacturer LOINC®
		HBsAb, quantitative	16935-9	Hepatitis B virus surface Ab:ACnc:Pt:Ser:Qn	5193-8	Hepatitis B virus surface Ab [Presence] in Serum by Immunoassay	Quantitative LOINC® vs qualitative by the manufacturer
Pilot Site 3	Roche Cobas c 702	Blood urea nitrogen	3094-0	BUN	14937-7	Urea nitrogen [Moles/volume] in Serum or Plasma	Different units of measure: mass/volume versus moles/volume
		AST (SGOT)	1920-8	Aspartate aminotransferase (AST)	30239-8	Aspartate aminotransferase [Enzymatic activity/volume] in Serum or Plasma by With P-5'-P	Methodless LOINC®—still a valid LOINC®, but not as granular as the manufacturer LOINC®
Pilot Site 5	Roche Cobas c 702	BUN	3094-0	Urea nitrogen [Mass/volume] in Serum or Plasma	14937-7	Urea nitrogen [Moles/volume] in Serum or Plasma	Different units of measure: mass/volume versus moles/volume
		Aspartate aminotransferase (AST)	1920-8	Aspartate aminotransferase [Enzymatic activity/volume] in Serum or Plasma	30239-8	Aspartate aminotransferase [Enzymatic activity/volume] in Serum or Plasma by With P-5'-P	Methodless LOINC®—still a valid LOINC®, but not as granular as the manufacturer LOINC®

^aWe identified 136 LOINC® codes in the manufacturer LIVD files that mismatch LOINC® codes used at pilot site medical centers. This table shows a representative sample of these mismatches.