title: Epidemiology of overdose episodes from the period prior to hospitalization for drug poisoning until discharge in Japan: An exploratory descriptive study using a nationwide claims database.
abstract: BACKGROUND
  Little is known about the nationwide epidemiology of the annual rate, causative substance, and clinical course of overdose-related admission. We aimed to describe the epidemiology of overdose episodes from the period prior to hospitalization for drug poisoning until discharge to home.
  
  
  METHODS
  We assessed all cases of admission due to overdose (21,663 episodes) in Japan from October 2012 through September 2013 using the National Database of Health Insurance Claims and Specific Health Checkups of Japan.
  
  
  RESULTS
  The annual rate of overdose admission was 17.0 per 100,000 population. Women exhibited two peaks in admission rates at 19-34 years (40.9 per 100,000) and ≥75 years (27.8 per 100,000). Men exhibited one peak in the admission rate at ≥75 years (23.7 per 100,000). Within 90 days prior to overdose, ≥60% and ≥9% of patients aged 19-49 years received a prescription for benzodiazepines and barbiturates, respectively. In addition, 59% of patients aged ≥75 years received a prescription for benzodiazepines prior to overdose, 47% had a history of congestive heart failure, and 24% had a diagnosis of poisoning by cardiovascular drugs. The proportion of patients with recent psychiatric treatments decreased with age (65.1% in those aged 35-49 years and 13.9% in those aged ≥75 years).
  
  
  CONCLUSIONS
  The findings emphasize the need for overdose prevention programs that focus on psychiatric patients aged 19-49 years who are prescribed benzodiazepines or barbiturates and on non-psychiatric patients aged ≥75 years who are prescribed benzodiazepines or digitalis.
authors.affiliation: Research Department, Institute for Health Economics and Policy, Association for Health Economics Research and Social Insurance and Welfare, Tokyo, Japan. Electronic address: yokumura@blue.zero.jp.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Okumura
authors.affiliation: Research Department, Institute for Health Economics and Policy, Association for Health Economics Research and Social Insurance and Welfare, Tokyo, Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Sakata
authors.affiliation: Department of Biostatistics, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Department of Mental Health Policy and Evaluation, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nishi
authors.affiliation: Department of Mental Health Policy and Evaluation, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Japan.
authors.forename: Hisateru
authors.initials: H
authors.lastname: Tachimori
mesh_terms: D000328:Adult; D000368:Aged; D001463:Barbiturates / Q000506:poisoning / Q000627:therapeutic use; D001569:Benzodiazepines / Q000506:poisoning / Q000627:therapeutic use; D016208:Databases, Factual; D004071:Digitalis Glycosides / Q000506:poisoning / Q000627:therapeutic use; D062787:Drug Overdose / Q000453:epidemiology*; D005260:Female; D006760:Hospitalization; D006801:Humans; D007345:Insurance Claim Review; D007348:Insurance, Health; D007564:Japan / Q000453:epidemiology; D008297:Male; D001523:Mental Disorders / Q000188:drug therapy; D008875:Middle Aged; D010351:Patient Discharge; D011041:Poisoning / Q000628:therapy; D012307:Risk Factors
chemical_list: D001463:Barbiturates; D004071:Digitalis Glycosides; D001569:Benzodiazepines
keywords: Benzodiazepines; Digitalis; Drug poisoning; Geographical variation; Self-poisoning