Abstract

Background: Polypharmacy (commonly defined as the use of five or more medicines) is increasing in the elderly. It’s been known to increase the risk of adverse drug events. However, its impact on outcomes like mortality or hospitalization has not been clarified.
Objective: The aim of this research was to determine the association between polypharmacy and mortality, falls, Adverse Drug Reactions (ADR) and hospitalisation in the elderly at one and five years.
Methods: A retrospective cross-sectional study was carried out using 1000 patients aged 75 years and above from the Clinical Practice Research Datalink (CPRD). The follow up period for the one and five years analysis were January 2010 to December 2011 and January 2010 to December 2014 respectively. Sociodemographic and clinical variables were retrieved using medical and product codes from the CPRD code browser. The association between polypharmacy (estimated as the average number of medicines at a cutoff point of >5 medicines) and mortality, falls, ADR and hospitalisation was determined using logistic regression analysis whiles confounding for age, sex, Charlson’s Comorbidity Index (CCI), previous hospitalisation and previous falls.
Results: Polypharmacy was associated with mortality and hospitalisation at one and five years. However, it was not associated with falls and ADR. Adjusted Odd Ratio (OR) for outcomes at one and five years were: mortality 10.30(5.4 – 19.50) and 1.89(1.4 – 2.5), hospitalisation 2.51(1.6 – 3.7) and 2.26(1.6 – 3.2), falls 0.57(0.2 – 1.7) and 1.38(0.8 – 2.3) and ADR 2.3(0.2 – 3.2) and 1.09(0.5 – 2.5) respectively.
Conclusion: Polypharmacy was found to be associated with mortality and hospitalisation at one and five years. The risk of association was higher at one year than five years. However, it was not associated with falls or ADR.