title: Polypharmacy, length of hospital stay, and in-hospital mortality among elderly patients in internal medicine wards. The REPOSI study.
abstract: OBJECTIVE
  We evaluated the prevalence and factors associated with polypharmacy and investigated the role of polypharmacy as a predictor of length of hospital stay and in-hospital mortality.
  
  
  METHODS
  Thirty-eight internal medicine wards in Italy participated in the Registro Politerapie SIMI (REPOSI) study during 2008. One thousand three hundred and thirty-two in-patients aged ≥65 years were enrolled. Polypharmacy was defined as the concomitant use of five or more medications. Linear regression analyses were used to evaluate predictors of length of hospital stay and logistic regression models for predictors of in-hospital mortality. Age, sex, Charlson comorbidity index, polypharmacy, and number of in-hospital clinical adverse events (AEs) were used as possible confounders.
  
  
  RESULTS
  The prevalence of polypharmacy was 51.9% at hospital admission and 67.0% at discharge. Age, number of drugs at admission, hypertension, ischemic heart disease, heart failure, and chronic obstructive pulmonary disease were independently associated with polypharmacy at discharge. In multivariate analysis, the occurrence of at least one AE while in hospital was the only predictor of prolonged hospitalization (each new AE prolonged hospital stay by 3.57 days, p < 0.0001). Age [odds ratio (OR) 1.04; 95% confidence interval (CI) 1.01-1.08; p = 0.02), comorbidities (OR 1.18; 95% CI 1.12-1.24; p < 0.0001), and AEs (OR 6.80; 95% CI 3.58-12.9; p < 0.0001) were significantly associated with in-hospital mortality.
  
  
  CONCLUSIONS
  Although most elderly in-patients receive polypharmacy, in this study, it was not associated with any hospital outcome. However, AEs were strongly correlated with a longer hospital stay and higher mortality risk.
authors.affiliation: Laboratory for Quality Assessment of Geriatric Therapies and Services, Mario Negri Institute for Pharmacological Research, via Giuseppe La Masa, 19, 20156 Milan, Italy. nobili@marionegri.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Nobili
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Licata
authors.forename: Francesco
authors.initials: F
authors.lastname: Salerno
authors.forename: Luca
authors.initials: L
authors.lastname: Pasina
authors.forename: Mauro
authors.initials: M
authors.lastname: Tettamanti
authors.forename: Carlotta
authors.initials: C
authors.lastname: Franchi
authors.forename: Luigi
authors.initials: L
authors.lastname: De Vittorio
authors.forename: Alessandra
authors.initials: A
authors.lastname: Marengoni
authors.forename: Salvatore
authors.initials: S
authors.lastname: Corrao
authors.forename: Alfonso
authors.initials: A
authors.lastname: Iorio
authors.forename: Maura
authors.initials: M
authors.lastname: Marcucci
authors.forename: Pier Mannuccio
authors.initials: PM
authors.lastname: Mannucci
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D011307:Drug Prescriptions; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D007388:Internal Medicine / Q000379:methods / Q000592:standards*; D007558:Italy / Q000453:epidemiology; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D019338:Polypharmacy; D010818:Practice Patterns, Physicians'; D015995:Prevalence; D011446:Prospective Studies