title: Adverse drug reactions as a cause of hospital admissions: a 6-month experience in a single center in Greece.
abstract: BACKGROUND
  Adverse drug reactions (ADRs) are a significant cause of morbidity and mortality.
  
  
  METHODS
  A prospective study was conducted over a 6-month period. All patients consecutively admitted were enrolled in the study. Analysis included: (1) an evaluation of the frequency of ADR-related hospital admissions and their causality, severity, and preventability; (2) a description of the type of drugs involved; (3) a report of the most common clinical manifestations related to these ADRs; and (4) an assessment of the factors that were predictive of ADRs.
  
  
  RESULTS
  Seventy of the 548 admissions (12.8%) were related to an ADR. Hemorrhage represented the most common ADR (37.3%), followed by metabolic and renal events (10.8% each). The drugs most often involved were non-steroid anti-inflammatory drugs (NSAIDs), followed by diuretics, aspirin, oral anticoagulants, and oral hypoglycemic agents. A comparison between ADR and non-ADR-related admissions showed that mean number of medications and age were significantly higher for patients admitted for an ADR than for those who were not. Gender, chronic disease at admission, days of hospitalization, cognitive impairment, renal insufficiency, physical activity impairment, and use of psychoactive drugs did not differ between the two groups. In the multivariate analysis, number of drugs was the only independent predictor of ADR-related hospital admission (OR=1.064, 95% CI 1.019-1.109). In 13 of 70 (18.6%) ADR-related hospital admissions, ADRs were coded as severe.
  
  
  CONCLUSIONS
  ADRs are common causes of hospital admissions and may have important consequences. The most important determinant for ADR-related hospital admissions is the number of drugs taken.
authors.affiliation: 2nd Department of Medicine, Athens Medical School, Hippokration General Hospital, Athens, Greece. alexopou@ath.forthnet.gr
authors.forename: Alexandra
authors.initials: A
authors.lastname: Alexopoulou
authors.forename: Spyros P
authors.initials: SP
authors.lastname: Dourakis
authors.forename: Demosthenes
authors.initials: D
authors.lastname: Mantzoukis
authors.forename: Thomas
authors.initials: T
authors.lastname: Pitsariotis
authors.forename: Anna
authors.initials: A
authors.lastname: Kandyli
authors.forename: Melanie
authors.initials: M
authors.lastname: Deutsch
authors.forename: Athanasios J
authors.initials: AJ
authors.lastname: Archimandritis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D000925:Anticoagulants / Q000009:adverse effects; D004232:Diuretics / Q000009:adverse effects; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005260:Female; D006115:Greece / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007004:Hypoglycemic Agents / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000925:Anticoagulants; D004232:Diuretics; D007004:Hypoglycemic Agents