title: Adverse Drug Reaction-Related Hospitalizations in Elderly Australians: A Prospective Cross-Sectional Study in Two Tasmanian Hospitals.
abstract: Adverse drug reactions (ADRs) have been commonly cited as a major cause of hospital admissions in older individuals. However, despite the apparent magnitude of this problem, there are limited prospective data on ADRs as a cause of hospitalization in elderly medical patients.
  
  
  
  The objective of this study was to evaluate the proportion, clinical characteristics, causality, severity, preventability, and outcome of ADR-related admissions in older patients admitted to two Tasmanian hospitals.
  
  
  
  We conducted a prospective cross-sectional study at the Royal Hobart and Launceston General Hospitals in Tasmania, Australia. A convenience sample of patients, aged 65 years and older, undergoing unplanned overnight medical admissions was screened. ADR-related admissions were determined through expert consensus from detailed review of medical records and patient interviews. The causality, preventability and severity of each ADR-related admission were assessed.
  
  
  
  Of 1008 admissions, the proportion of potential ADR-related medical admissions was 18.9%. Most (88.5%) ADR-related admissions were considered preventable. Cardiovascular complaints (29.3%) represented the most common ADRs, followed by neuropsychiatric (20.0%) and renal and genitourinary disorders (15.2%). The most frequently implicated drug classes were diuretics (23.9%), agents acting on the renin angiotensin system (16.4%), β-blocking agents (7.1%), antidepressants (6.9%), and antithrombotic agents (6.9%). Application of the Naranjo algorithm found 5.8% definite, 70.1% probable, and 24.1% possible ADRs. ADR severity was rated moderate and severe in 97.9% and 2.1% of admissions, respectively. For most (93.2%) ADR-related admissions the ADR resolved and the patient recovered.
  
  
  
  Hospitalization due to an ADR is a common occurrence in this older population. There is need for future studies to implement and evaluate interventions to reduce the risk of ADR-related admissions in elderly populations.
authors.affiliation: Unit for Medication Outcomes Research and Education, Division of Pharmacy, Faculty of Health, School of Medicine, University of Tasmania, Hobart, TAS, 7001, Australia. Nibu.ParameswaranNair@utas.edu.au.
authors.forename: Nibu
authors.initials: N
authors.lastname: Parameswaran Nair
authors.affiliation: Unit for Medication Outcomes Research and Education, Division of Pharmacy, Faculty of Health, School of Medicine, University of Tasmania, Hobart, TAS, 7001, Australia.
authors.forename: Leanne
authors.initials: L
authors.lastname: Chalmers
authors.affiliation: Unit for Medication Outcomes Research and Education, Division of Pharmacy, Faculty of Health, School of Medicine, University of Tasmania, Hobart, TAS, 7001, Australia.
authors.forename: Bonnie J
authors.initials: BJ
authors.lastname: Bereznicki
authors.affiliation: Unit for Medication Outcomes Research and Education, Division of Pharmacy, Faculty of Health, School of Medicine, University of Tasmania, Hobart, TAS, 7001, Australia.
authors.forename: Colin
authors.initials: C
authors.lastname: Curtain
authors.affiliation: Unit for Medication Outcomes Research and Education, Division of Pharmacy, Faculty of Health, School of Medicine, University of Tasmania, Hobart, TAS, 7001, Australia.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Peterson
authors.affiliation: Unit for Medication Outcomes Research and Education, Division of Pharmacy, Faculty of Health, School of Medicine, University of Tasmania, Hobart, TAS, 7001, Australia.|Royal Hobart Hospital, Hobart, TAS, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Connolly
authors.affiliation: Unit for Medication Outcomes Research and Education, Division of Pharmacy, Faculty of Health, School of Medicine, University of Tasmania, Hobart, TAS, 7001, Australia.
authors.forename: Luke R
authors.initials: LR
authors.lastname: Bereznicki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D003430:Cross-Sectional Studies; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D010343:Patient Admission; D011159:Population Surveillance; D011446:Prospective Studies; D012307:Risk Factors; D013648:Tasmania / Q000453:epidemiology