COMBINING LABORATORY DATA SETS FROM MULTIPLE INSTITUTIONS USING THE LOGICAL OBSERVATION IDENTIFIER NAMES AND CODES (LOINC)

A standard set of names and codes for laboratory test results is criti cal for any endeavor requiring automated data pooling, including multi -institutional research and cross-facility patient care. This need has led to the development of the logical observation identifier names an d codes (LOINC) database and its test-naming convention. This study is an expansion of a pilot study using LOINC to exchange laboratory data between Columbia University Medical Center in New York and Barnes Hos pital at Washington University in St. Louis, where we described comple xities and ambiguities that arose in the LOINC coding process (D.M. Ba orto, J.J. Cimino, C.A. Parvin, M.G. Kahn, Proc. Am. Med. Inf. Assoc. 1997). For the present study, we required the same two medical centers to again extract raw laboratory data from their local information sys tem for a defined patient population, translate tests into LOINC and p rovide aggregate data which could then be used to compare laboratory u tilization. Here we examine a larger number of tests from each site wh ich have been recoded using an updated version of the LOINC database. We conclude that the coding of local tests into LOINC can often be com plex, especially the 'Kind of Property' field and apparently trivial d ifferences in choices made by individual institutions can result in no nmatches in electronically pooled data. In the present study, 75% of f ailures to match the same tests between different institutions using L OINC codes were due to differences in local coding choices. LOINC has the potential to eliminate the need for derailed human inspection duri ng the pooling of laboratory data from diverse sites and perhaps even a built-in capability to adjust matching stringency by selecting subse ts of LOINC fields required to match. However, a quality standard codi ng procedure is required and examples highlighted in this paper may re quire special attention while mapping to LOINC. (C) 1998 Elsevier Scie nce Ireland Ltd. All rights reserved.