Comparative analysis of epilepsy abstracts and a MEDLARS bibliography

Bibliographic retrievals on epilepsy prepared by MEDLARS and Excerpta Medica Foundation (EMF) monthly during 1968 were comparatively analyzed. EMF retrieved 1,116 citations with an average delay of 5.41 months, compared to 1,006 citations retrieved by MEDLARS with an average delay of 6.45 months. Differences in size of retrieval and delay between the systems were not significant. A total of 365 journals were represented, but a smaller group of ninety-one journals with citations in both retrievals formed a "core" of productive journals yielding over half the output of both systems. About 300 articles were cited in both searches, leaving 800 citations retrieved by EMF but not by MEDLARS and 700 citations retrieved by MEDLARS but not by EMF. Thus neither system was felt to provide comprehensive coverage of the epilepsy literature. Discrepancies in retrieval were found to be due primarily to indexing and retrieval procedures and not to coverage of different journals by the two systems.