title: Hospital admissions due to adverse drug reactions in the elderly. A meta-analysis.
abstract: BACKGROUND
  It is currently admitted that adverse drug reactions (ADRs) account for a great burden of disease. Of particular concern are ADR-induced hospital admissions, particularly in the elderly; they receive most of the medications and they are the most prone to develop ADRs. Therefore, our aim was to carry out a study of ADR-induced hospital admissions focused on the elderly population.
  
  
  METHODS
  For the purpose, a systematic review and meta-analysis was performed of those studies addressing ADR-induced hospital admissions in patients over 60 years of age. A computerized search of the literature was carried out in the main databases. The search spans from 1988 to 2015. A pooled prevalence figure was calculated with 95% CIs; heterogeneity was also explored.
  
  
  RESULTS
  The final number of selected articles was 42; all of them were published between January 1988 and August 2015. The overall average percentage of hospital admissions was 8.7% (95% CI, 7.6-9.8%). NSAIDs are one of the medication classes more frequently related to these admissions (percentages range from 2.3 to 33.3%). Inappropriate medication as a risk factor was studied in nine studies, four found a statistically significant relationship between those medications and hospital admissions.
  
  
  CONCLUSIONS
  Circa one in ten hospital admissions of older patients are due to ADRs. A great burden of disease is due to a few and identifiable medication classes; in most of the cases, the reactions are well known and probably preventable. A sense of purpose and determination is needed by health authorities to face this problem. Doctors, on their part, should be aware when prescribing some specific identifiable medications to these patients.
  
  
  CONCLUSIONS
  1. One in ten hospital admissions in older patients are due to ADRs; NSAIDs are the medications the most related with these admissions, followed by other common medications used in patients of this age, such as beta-blockers. 2. A great burden of disease is due to medications that are intended to cure or alleviate disease; this burden of disease is not only painful for the patients but also costly. 3. Identified risk factors are particular medication classes and polymedication. In most of the cases, reactions are probably preventable.
authors.affiliation: Departamento de Farmacología de la Facultad de Medicina de la Universidad Nacional Mayor de San Marcos, Lima District, Peru.|Centro de Investigación de Seguridad de Medicamentos de la Facultad de Medicina de la Universidad de San Martín de Porres, Calandrias, Peru.
authors.forename: T J
authors.initials: TJ
authors.lastname: Oscanoa
authors.affiliation: Instituto de Investigación de la Facultad de Medicina de la Universidad de San Martín de Porres, Calandrias, Peru.
authors.forename: F
authors.initials: F
authors.lastname: Lizaraso
authors.affiliation: Centro de Estudios sobre la Seguridad de los Medicamentos (CESME), Universidad de Valladolid, Valladolid, Spain. carvajal@ife.uva.es.|School of Medicine, Ramón y Cajal, 7, 47005, Valladolid, Spain. carvajal@ife.uva.es.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Carvajal
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D000368:Aged; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D057970:Inappropriate Prescribing / Q000706:statistics & numerical data; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data; D019338:Polypharmacy; D012307:Risk Factors
keywords: ADRs; Elderly patients; Hospital admissions; Meta-analysis