Investigating the semantic interoperability of laboratory data exchanged using LOINC codes in three large institutions.

LOINC codes are seeing increased use in many organizations. In this study, we examined the barriers to semantic interoperability that still exist in electronic data exchange of laboratory results even when LOINC codes are being used as the observation identifiers. We analyzed semantic interoperability of laboratory data exchanged using LOINC codes in three large institutions. To simplify the analytic process, we divided the laboratory data into quantitative and non-quantitative tests. The analysis revealed many inconsistencies even when LOINC codes are used to exchange laboratory data. For quantitative tests, the most frequent problems were inconsistencies in the use of units of measure: variations in the strings used to represent units (unrecognized synonyms), use of units that result in different magnitudes of the numeric quantity, and missing units of measure. For non-quantitative tests, the most frequent problems were acronyms/synonyms, different classes of elements in enumerated lists, and the use of free text. Our findings highlight the limitations of interoperability in current laboratory reporting.