Frontiers in Drug Safety and Regulation (Feb 2023)

Natural language processing for automated triage and prioritization of individual case safety reports for case-by-case assessment

  • Thomas Lieber,
  • Helen R. Gosselt,
  • Pelle C. Kools,
  • Okko C. Kruijssen,
  • Stijn N. C. Van Lierop,
  • Linda Härmark,
  • Florence P. A. M. Van Hunsel

DOI
https://doi.org/10.3389/fdsfr.2023.1120135
Journal volume & issue
Vol. 3

Abstract

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Objective: To improve a previously developed prediction model that could assist in the triage of individual case safety reports using the addition of features designed from free text fields using natural language processing.Methods: Structured features and natural language processing (NLP) features were used to train a bagging classifier model. NLP features were extracted from free text fields. A bag-of-words model was applied. Stop words were deleted and words that were significantly differently distributed among the case and non-case reports were used for the training data. Besides NLP features from free-text fields, the data also consisted of a list of signal words deemed important by expert report assessors. Lastly, variables with multiple categories were transformed to numerical variables using the weight of evidence method.Results: the model, a bagging classifier of decision trees had an AUC of 0.921 (95% CI = 0.918–0.925). Generic drug name, info text length, ATC code, BMI and patient age. were most important features in classification.Conclusion: this predictive model using Natural Language Processing could be used to assist assessors in prioritizing which future ICSRs to assess first, based on the probability that it is a case which requires clinical review.

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