title: Clinical and economic impact of adverse drug reactions in hospitalized patients.
abstract: OBJECTIVE
  To identify the classes of drugs that most commonly cause adverse drug reactions (ADRs) and the characteristics of these ADRs and to determine the economic impact of ADRs on patients' length of stay and hospitalization costs.
  
  
  METHODS
  Data on ADRs from patients admitted to a hospital in New Jersey were collected, studied, and analyzed over a five-month period. To determine the economic impact of ADRs, patients who experienced ADRs during hospitalization were matched to controls. Each ADR was rated with regard to its severity, the patients' outcomes were determined, and specific classes of medications were identified as particularly causative of ADRs.
  
  
  RESULTS
  A total of 196 patients experienced ADRs; 131 of these individuals were matched with 1338 patients who did not experience an ADR, based on their diagnosis-related group code. The leading causal drugs according to therapeutic class were antiinfective (17%), cardiovascular (17%), antineoplastic (15%), and analgesics/antiinflammatory agents (15%). The organ systems most often affected were gastrointestinal (24%), dermatologic (19%), and immune systems (15%). The mean length of stay per patient differed significantly between the ADR case group and matched control group (10.6 vs. 6.8 d; p = 0.003), as did the total hospitalization cost ($22775 vs. $17292; p = 0.025).
  
  
  CONCLUSIONS
  Length of hospital stay and total hospitalization costs were significantly higher for patients experiencing ADRs than those who did not experience ADRs. ADR reporting systems in hospitals need to be changed and strengthened to decrease the incidence of avoidable reactions.
authors.affiliation: College of Pharmacy, Rutgers-The State University of New Jersey, Piscataway 08854-8020, USA. dsuh@rci.rutgers.edu
authors.forename: D C
authors.initials: DC
authors.lastname: Suh
authors.forename: B S
authors.initials: BS
authors.lastname: Woodall
authors.forename: S K
authors.initials: SK
authors.lastname: Shin
authors.forename: E R
authors.initials: ER
authors.lastname: Hermes-De Santis
mesh_terms: D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D017677:Age Distribution; D000368:Aged; D004358:Drug Therapy / Q000191:economics; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D017048:Health Care Costs; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007902:Length of Stay; D008297:Male; D008875:Middle Aged