Evaluating congruence between laboratory LOINC value sets for quality measures, public health reporting, and mapping common tests.

Laboratory test results are important for secondary data uses like quality measures and public health reporting, but mapping local laboratory codes to LOINC is a challenge. We evaluated the congruence between laboratory LOINC value sets for quality measures, public health reporting, and mapping common tests. We found a modest proportion of the LOINC codes from the Value Set Authority Center (VSAC) were present in the LOINC Top 2000 Results (16%) and the Reportable Condition Mapping Table (52%), and only 25 terms (3%) were shared with the Notifiable Condition Detector Top 129. More than a third of the VSAC Quality LOINCs were unique to that value set. A relatively small proportion of the VSAC Quality LOINCs were used by our hospital laboratories. Our results illustrate how mapping based only on test frequency might hinder these secondary uses of laboratory test results.