title: Drug overdose surveillance using hospital discharge data.
abstract: OBJECTIVE
  We compared three methods for identifying drug overdose cases in inpatient hospital discharge data on their ability to classify drug overdoses by intent and drug type(s) involved.
  
  
  METHODS
  We compared three International Classification of Diseases, Ninth Revision, Clinical Modification code-based case definitions using Kentucky hospital discharge data for 2000-2011. The first definition (Definition 1) was based on the external-cause-of-injury (E-code) matrix. The other two definitions were based on the Injury Surveillance Workgroup on Poisoning (ISW7) consensus recommendations for national and state poisoning surveillance using the principal diagnosis or first E-code (Definition 2) or any diagnosis/E-code (Definition 3).
  
  
  RESULTS
  Definition 3 identified almost 50% more drug overdose cases than did Definition 1. The increase was largely due to cases with a first-listed E-code describing a drug overdose but a principal diagnosis that was different from drug overdose (e.g., mental disorders, or respiratory or circulatory system failure). Regardless of the definition, more than 53% of the hospitalizations were self-inflicted drug overdoses; benzodiazepines were involved in about 30% of the hospitalizations. The 2011 age-adjusted drug overdose hospitalization rate in Kentucky was 146/100,000 population using Definition 3 and 107/100,000 population using Definition 1.
  
  
  CONCLUSIONS
  The ISW7 drug overdose definition using any drug poisoning diagnosis/E-code (Definition 3) is potentially the highest sensitivity definition for counting drug overdose hospitalizations, including by intent and drug type(s) involved. As the states enact policies and plan for adequate treatment resources, standardized drug overdose definitions are critical for accurate reporting, trend analysis, policy evaluation, and state-to-state comparison.
authors.affiliation: Kentucky Injury Prevention and Research Center, Lexington, KY ; University of Kentucky, College of Public Health, Department of Biostatistics, Lexington, KY.
authors.forename: Svetla
authors.initials: S
authors.lastname: Slavova
authors.affiliation: Kentucky Injury Prevention and Research Center, Lexington, KY ; University of Kentucky, College of Public Health, Department of Preventive Medicine and Environmental Health, Lexington, KY.
authors.forename: Terry L
authors.initials: TL
authors.lastname: Bunn
authors.affiliation: University of Kentucky, College of Pharmacy, Department of Pharmacy Practice and Science, Lexington, KY ; University of Kentucky, Institute for Pharmaceutical Outcomes and Policy, Lexington, KY.
authors.forename: Jeffery
authors.initials: J
authors.lastname: Talbert
mesh_terms: D000700:Analgesics / Q000506:poisoning; D000925:Anticoagulants / Q000506:poisoning; D059019:Clinical Coding / Q000379:methods / Q000592:standards*; D062787:Drug Overdose / Q000145:classification / Q000453:epidemiology*; D006801:Humans; D013287:Illicit Drugs / Q000506:poisoning; D033182:Intention; D038801:International Classification of Diseases; D007629:Kentucky / Q000453:epidemiology; D010351:Patient Discharge / Q000706:statistics & numerical data*; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000145:classification*; D011041:Poisoning / Q000145:classification / Q000209:etiology; D011159:Population Surveillance / Q000379:methods*; D011619:Psychotropic Drugs / Q000506:poisoning
chemical_list: D000700:Analgesics; D000925:Anticoagulants; D013287:Illicit Drugs; D004364:Pharmaceutical Preparations; D011619:Psychotropic Drugs