Automated identification of pediatric appendicitis score in emergency department notes using natural language processing

Objective: The goal of this project was development of a software tool to detect documentation of Pediatric Appendicitis Score (PAS) within electronic emergency department (ED) notes. The overarching purpose was assessment of diagnostic imaging practices when PAS falls outside of a certain range, since minimizing patients' radiation exposure is desired. Methods: 15074 ED notes were collected from visits between July 2011–Aug. 2016. Notes were labeled as having PAS documented (PAS+) or not (PAS-). 12562 semistructured notes were split into 60% training, 20% validation, and 20% testing. An automated procedure was developed to label data, preprocess notes, extract features, construct three classification models, and compare the models. The selected model was also evaluated on a second testing set of 2512 hand-labeled (BN) unstructured notes using F1-score. Results: The Logistic Regression (LR) model was selected for best F1-score on the validation set (0.9874). This model's F1-score on the human-labeled testing set of unstructured data (0.8391) outperformed the previous method (0.3435). Discussion: The selected LR model demonstrated an improvement upon the previous method when evaluated on manually labeled unstructured data (no overlap in 95% CI). Conclusion: While the LR classifier was trained and selected in an automated way, it still performed well compared to human performance. This tool can be used to expedite manual chart review for identification of PAS within ED notes.