Analysis of Cross-Institutional Medication Information Annotations in Clinical Notes

A large amount of medication information resides in unstructured text in electronic medical records, which requires advanced techniques to be properly mined. In clinical notes, medication information follows certain semantic patterns (e.g., medication, dosage, frequency, mode, etc.). Some medication descriptions contain additional word(s) between medication attributes. Therefore, it is essential to understand the semantic patterns as well as the patterns of the context interspersed among them (i.e., context patterns) to effectively extract comprehensive medication information. In this paper we examined both semantic and context patterns and compared those found in Mayo Clinic and i2b2 challenge data. We found that some variations exist between the institutions but the dominant patterns are common.