title: Polypharmacy in the Elderly: A Marker of Increased Risk of Mortality in a Population-Based Prospective Study (NEDICES).
abstract: BACKGROUND
  Little information is available on the potential association between polypharmacy and risk of mortality.
  
  
  OBJECTIVE
  To determine in a population-based study whether polypharmacy is associated with increased risk of mortality in elderly persons.
  
  
  METHODS
  In this population-based, prospective study of 5,052 people aged 65 years and older (Neurological Disorders in Central Spain), current medications were recorded. Cox proportional hazards models, adjusted for sociodemographics and comorbidity factors, were used to assess the risk of death up to 13.3 years later, comparing the polypharmacy group (≥6 drugs) to those who were taking 1-5 drugs and those in a nonmedicated group (0 drugs).
  
  
  RESULTS
  Out of 5,052 participants, 2,550 (50.5%) died over a median follow-up of 6.5 years, including 361 (28.8%) deaths among 931 nonmedicated participants, 1,946 (51.4%) deaths among 3,787 participants taking 1-5 drugs daily, and 243 (72.8%) among 334 participants on polypharmacy. In an unadjusted Cox model, risk of mortality was increased in participants on polypharmacy [hazard ratio (HR) = 2.78, 95% confidence interval [CI]: 2.36-3.27, p < 0.001) and in those taking between 1 and 5 drugs (HR = 1.47, 95% CI: 1.31-1.64, p < 0.001) versus those who were nonmedicated (reference group). In a Cox model that adjusted for a variety of demographic factors and comorbidities, HR remained increased in participants on polypharmacy (HR = 1.83, 95% CI: 1.51-2.21, p < 0.001).
  
  
  CONCLUSIONS
  This study provides evidence that polypharmacy is associated with increased risk of mortality in elderly people. The extent to which polypharmacy is the proximate cause rather than a marker of this increase risk remains to be determined.
authors.affiliation: 'Eras del Bosque' Health Center, Palencia, Spain.
authors.forename: Candelas
authors.initials: C
authors.lastname: Gómez
authors.forename: Saturio
authors.initials: S
authors.lastname: Vega-Quiroga
authors.forename: Félix
authors.initials: F
authors.lastname: Bermejo-Pareja
authors.forename: María José
authors.initials: MJ
authors.lastname: Medrano
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
authors.forename: Julián
authors.initials: J
authors.lastname: Benito-León
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002423:Cause of Death; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D019338:Polypharmacy; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012959:Socioeconomic Factors; D013030:Spain / Q000453:epidemiology