title: Using natural language processing to identify problem usage of prescription opioids.
abstract: BACKGROUND
  Accurate and scalable surveillance methods are critical to understand widespread problems associated with misuse and abuse of prescription opioids and for implementing effective prevention and control measures. Traditional diagnostic coding incompletely documents problem use. Relevant information for each patient is often obscured in vast amounts of clinical text.
  
  
  OBJECTIVE
  We developed and evaluated a method that combines natural language processing (NLP) and computer-assisted manual review of clinical notes to identify evidence of problem opioid use in electronic health records (EHRs).
  
  
  METHODS
  We used the EHR data and text of 22,142 patients receiving chronic opioid therapy (≥70 days' supply of opioids per calendar quarter) during 2006-2012 to develop and evaluate an NLP-based surveillance method and compare it to traditional methods based on International Classification of Disease, Ninth Edition (ICD-9) codes. We developed a 1288-term dictionary for clinician mentions of opioid addiction, abuse, misuse or overuse, and an NLP system to identify these mentions in unstructured text. The system distinguished affirmative mentions from those that were negated or otherwise qualified. We applied this system to 7336,445 electronic chart notes of the 22,142 patients. Trained abstractors using a custom computer-assisted software interface manually reviewed 7751 chart notes (from 3156 patients) selected by the NLP system and classified each note as to whether or not it contained textual evidence of problem opioid use.
  
  
  RESULTS
  Traditional diagnostic codes for problem opioid use were found for 2240 (10.1%) patients. NLP-assisted manual review identified an additional 728 (3.1%) patients with evidence of clinically diagnosed problem opioid use in clinical notes. Inter-rater reliability among pairs of abstractors reviewing notes was high, with kappa=0.86 and 97% agreement for one pair, and kappa=0.71 and 88% agreement for another pair.
  
  
  CONCLUSIONS
  Scalable, semi-automated NLP methods can efficiently and accurately identify evidence of problem opioid use in vast amounts of EHR text. Incorporating such methods into surveillance efforts may increase prevalence estimates by as much as one-third relative to traditional methods.
authors.affiliation: Group Health Research Institute, 1700 Minor Ave., Suite 1500, Seattle, WA 98101, United States.
authors.forename: David S
authors.initials: DS
authors.lastname: Carrell
authors.affiliation: Group Health Research Institute, 1700 Minor Ave., Suite 1500, Seattle, WA 98101, United States. Electronic address: carrell.d@ghc.org.
authors.forename: David
authors.initials: D
authors.lastname: Cronkite
authors.affiliation: North America Medical Affairs, Global Innovative Pharma, Pfizer, Inc., New York, NY, United States.
authors.forename: Roy E
authors.initials: RE
authors.lastname: Palmer
authors.affiliation: Group Health Research Institute, 1700 Minor Ave., Suite 1500, Seattle, WA 98101, United States.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Saunders
authors.affiliation: North America Medical Affairs, Global Innovative Pharma, Pfizer, Inc., New York, NY, United States.
authors.forename: David E
authors.initials: DE
authors.lastname: Gross
authors.affiliation: Outcomes & Evidence, Global Health & Value, Pfizer Inc., New York, New York, United States.
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Masters
authors.affiliation: North America Medical Affairs, Global Innovative Pharma, Pfizer, Inc., New York, NY, United States.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Hylan
authors.affiliation: Group Health Research Institute, 1700 Minor Ave., Suite 1500, Seattle, WA 98101, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Von Korff
mesh_terms: D057225:Data Mining / Q000379:methods; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D057286:Electronic Health Records / Q000706:statistics & numerical data*; D006801:Humans; D057970:Inappropriate Prescribing / Q000706:statistics & numerical data*; D009292:Narcotic Antagonists / Q000627:therapeutic use*; D009323:Natural Language Processing; D009293:Opioid-Related Disorders / Q000453:epidemiology* / Q000517:prevention & control; D010146:Pain / Q000453:epidemiology* / Q000517:prevention & control*; D010363:Pattern Recognition, Automated / Q000379:methods; D015995:Prevalence; D012307:Risk Factors; D018875:Vocabulary, Controlled; D014861:Washington / Q000453:epidemiology
chemical_list: D009292:Narcotic Antagonists
keywords: Computer-assisted records review; Natural language processing; Opioid-related disorders; Surveillance