title: MedTime: a temporal information extraction system for clinical narratives.
abstract: Temporal information extraction from clinical narratives is of critical importance to many clinical applications. We participated in the EVENT/TIMEX3 track of the 2012 i2b2 clinical temporal relations challenge, and presented our temporal information extraction system, MedTime. MedTime comprises a cascade of rule-based and machine-learning pattern recognition procedures. It achieved a micro-averaged f-measure of 0.88 in both the recognitions of clinical events and temporal expressions. We proposed and evaluated three time normalization strategies to normalize relative time expressions in clinical texts. The accuracy was 0.68 in normalizing temporal expressions of dates, times, durations, and frequencies. This study demonstrates and evaluates the integration of rule-based and machine-learning-based approaches for high performance temporal information extraction from clinical narratives.
authors.affiliation: Department of Management Information Systems, University of Arizona, Tucson, AZ 85721, USA. Electronic address: yklin@email.arizona.edu.
authors.forename: Yu-Kai
authors.initials: YK
authors.lastname: Lin
authors.affiliation: Department of Management Information Systems, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Hsinchun
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Medicine, College of Medicine, University of Arizona, Tucson, AZ 85724, USA.
authors.forename: Randall A
authors.initials: RA
authors.lastname: Brown
mesh_terms: D000465:Algorithms; D057286:Electronic Health Records; D006801:Humans; D008490:Medical Informatics / Q000379:methods*; D033262:Narration; D009323:Natural Language Processing
keywords: Event recognition; Temporal expression recognition and normalization; Temporal information extraction; i2b2