Polypharmacy, length of hospital stay, and in-hospital mortality among elderly patients in internal medicine wards. The REPOSI study
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.
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.
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.
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.
KeywordsElderly Polypharmacy Hospital stay In-hospital mortality
We thank Professor Farncesco Violi, President of the Italian Society of Internal Medicine, for his help and encouragement. We are grateful to Judith Baggott for editorial assistance.
Carlotta Franchi holds a fellowship granted by Rotary Clubs Milano Naviglio Grande San Carlo, Milano Scala and Inner Wheel Milano San Carlo.
Conflict of interest
All the authors declare that no conflict of interest exist. All the authors state that they have a full control of data and that they agree to allow the journal to review their data if requested.
- 15.Lund BC, Camahan RM, Egge JA, Chrischilles EA, Kaboli PJ 2010 Inappropriate prescribing predicts adverse drug events in older adults. Ann Pharmacother. doi: 10.1345/aph.1M657
- 31.World Health Organization (1987) International Classification of Diseases, Injuries, and Causes of Death. Ninth Revision (ICD-9). Geneva: World Health Organization. http://icd9cm.chrisendres.com/. Accessed 12 July 2010
- 33.World Health Organization. Guidelines for ATC Classification. Sweden, WHO Collaborating Centre for Drug Statistics Methodology, Norway and Nordic Councils on Medicines, 1990Google Scholar
- 36.Pasina L, Nobili A, Tettamanti M, Salerno F, Corrao S, Bonazzi J, Vicidomini R, Mannucci PM (2009) A nome del partecipanti al Progetto Registro Politerapie SIMI. Utilizzo e appropriatezza d’uso dei farmaci anti-ulcera peptica/reflusso gastroesofageo in una coorte di anziani ricoverati in reparti di medicina interna. Intern Emerg Med 4:S69CrossRefGoogle Scholar
- 39.Knight EL, Avorn J (2001) Quality indicators for appropriate medication use in vulnerable elders. Intern Med 135:703–710Google Scholar