title: Risk factors associated with adverse drug events among older adults in emergency department.
abstract: BACKGROUND
  Little is known about the emergency department (ED) visits from drug-related injury among older adults in Taiwan. This study seeks to identify risk factors associated with adverse drug events (ADEs) leading to ED visits.
  
  
  METHODS
  We prospectively conducted a case-control study of patients 65years and older presenting to the ED. ED visits between March 1, 2009 and Feb 28, 2010 identified by investigators for suspected ADEs were further assessed by using the Naranjo Adverse Drug Reaction probability scale. For each patient with an ADE, a control was selected and time-matched from the ED population of the study hospital. The association between the risk of adverse drug events and triage, age, gender, serum alanine transaminase (ALT), serum creatinine, number of medications, and Charlson Comorbidity Index scores were analyzed using logistic regression.
  
  
  RESULTS
  Of 20,628 visits, 295 ADEs were physician-documented in older adults. Independent risk factors for ADEs included number of medications (adjusted odds ratio [OR]=4.1; 95% confidence interval [CI] 2.4-6.9 for 3-7 drugs; adjusted OR=6.4; 95% CI 3.7-11.0 for 8 or more drugs) and increased concentration of serum creatinine (adjusted OR=1.5; 95% CI 1.1-2.2). Diuretics, analgesics, cardiovascular agents, anti-diabetic agents and anticoagulants were the medications most commonly associated with an ADE leading to ED visits.
  
  
  CONCLUSIONS
  This study suggests that prevention efforts should be focused on older patients with renal insufficiency and polypharmacy who are using high risk medications such as anticoagulants, diuretics, cardiovascular agents, analgesics, and anti-diabetic agents.
authors.affiliation: Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Environmental and Occupational Health Sciences, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Rocky Mountain Poison and Drug Center, Denver Health, Denver, CO, USA.
authors.forename: Yen-Chia
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Emergency and Critical Care Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ju-Sing
authors.initials: JS
authors.lastname: Fan
authors.affiliation: Vigor Medical Institute, Taoyuan, Taiwan.
authors.forename: Min-Hui
authors.initials: MH
authors.lastname: Chen
authors.affiliation: Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Emergency and Critical Care Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Teh-Fu
authors.initials: TF
authors.lastname: Hsu
authors.affiliation: Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Emergency and Critical Care Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hsien-Hao
authors.initials: HH
authors.lastname: Huang
authors.affiliation: Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Emergency Medicine, Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Cheng
authors.affiliation: Institute of Emergency and Critical Care Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: hjyen@vghtpe.gov.tw.
authors.forename: David Hung-Tsang
authors.initials: DH
authors.lastname: Yen
authors.affiliation: Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Emergency Medicine, Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chun-I
authors.initials: CI
authors.lastname: Huang
authors.affiliation: Center for Geriatric and Gerontology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Family Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Liang-Kung
authors.initials: LK
authors.lastname: Chen
authors.affiliation: Institute of Environmental and Occupational Health Sciences, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Environmental and Occupational Medicine, Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Division of Clinical Toxicology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan. Electronic address: ccyang@vghtpe.gov.tw.
authors.forename: Chen-Chang
authors.initials: CC
authors.lastname: Yang
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000410:Alanine Transaminase / Q000097:blood; D000700:Analgesics / Q000009:adverse effects; D000925:Anticoagulants / Q000009:adverse effects; D002317:Cardiovascular Agents / Q000009:adverse effects; D016022:Case-Control Studies; D056486:Chemical and Drug Induced Liver Injury / Q000097:blood / Q000453:epidemiology*; D003404:Creatinine / Q000097:blood; D004232:Diuretics / Q000009:adverse effects; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000009:adverse effects; D016015:Logistic Models; D008297:Male; D019338:Polypharmacy; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000097:blood / Q000453:epidemiology*; D012307:Risk Factors; D012737:Sex Factors; D013624:Taiwan / Q000453:epidemiology
chemical_list: D000700:Analgesics; D000925:Anticoagulants; D002317:Cardiovascular Agents; D004232:Diuretics; D007004:Hypoglycemic Agents; D003404:Creatinine; D000410:Alanine Transaminase
keywords: Adverse drug event (ADE); Emergency department; Risk factors