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Prevalence and Risk of Polypharmacy among the Elderly in an Outpatient Setting

A Retrospective Cohort Study in the Emilia-Romagna Region, Italy

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Abstract

Background: Polypharmacy, the simultaneous taking of many medications, has been well documented and is a topic of much concern for those looking to improve the quality of care for the elderly. Elderly patients often develop complicated and multifactorial health states that require extensive pharmacotherapy, leaving this population at risk for exposure to drug-drug interactions and other adverse events. Previous literature supports an association between an increase in the rate of adverse events as the number of drugs taken by a patient increases.

Objective: We sought to evaluate the prevalence of polypharmacy, and to determine patient characteristics that are predictive of exposure to polypharmacy, in the elderly population of the Emilia-Romagna region in Italy.

Methods: We conducted a retrospective cohort study of the 2007 Emilia-Romagna outpatient pharmacy database linked with patient information available from a demographic file of approximately 1 million Emilia-Romagna residents aged ≥65 years. The cohort comprised 887 165 elderly subjects who had at least one prescription filled during the study year. Using the WHO’s defined daily dose (DDD) to determine the duration of treatment for a given drug, we defined a polypharmacy episode as overlapping treatment with five or more medications occurring for at least 1 day. The prevalence of polypharmacy was measured together with subject characteristics found to be predictive of polypharmacy exposure.

Results: A total of 349 689 elderly people in the population (39.4%) were exposed to at least one episode of polypharmacy during the study period. The prevalence of polypharmacy substantially increased with age and with a higher number of chronic conditions. Over 35% of those exposed to polypharmacy were exposed for 101 or more days of the year. The top three classes of medications involved in polypharmacy were antithrombotics, peptic ulcer disease and gastro-oesophageal reflux disease agents, and ACE inhibitors. The odds of exposure to polypharmacy were higher for older subjects, males and subjects living in urban areas.

Conclusions: This study provides evidence that the prevalence of polypharmacy in the elderly in Emilia-Romagna is substantial. Educational programmes should be developed to inform clinicians about the magnitude of the polypharmacy phenomenon and the patient characteristics associated with polypharmacy. Raising physicians’ awareness of polypharmacy may help to ensure safe, effective and appropriate use of medication in the elderly.

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Notes

  1. The PFN includes all medications marketed in Italy. It has a positive and a negative drug list, outlining which medicines will be reimbursed and which need to be paid for in full by patients, respectively. All essential medications, such as cardiovascular and antihyperglycaemic drugs, are reimbursed by the PFN; non-essential medications such as benzodiazepines, as well as any over-the-counter medications such as antitussive and cold drugs, are not reimbursed. All Italian citizens are entitled to access essential healthcare services, including PFNreimbursed medications.

  2. Because of the reimbursement process, information in the Emilia-Romagna pharmacy database is very accurate. The pharmacy database includes a unique, anonymous patient identification number, which has been used to link the pharmacy database with the demographic file. The linkage between the demographic file and the pharmacy database was virtually complete.

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Acknowledgements

This research was supported through a collaborative agreement between the Regional Health Care Agency, Assessorato alla Sanita’, Emilia-Romagna, Italy and Thomas Jefferson University, Philadelphia, PA, USA. Dr Slabaugh and Dr Abouzaid are enrolled in a fellowship in pharmacoeconomics and outcomes research sponsored by Ortho-McNeil-Janssen Scientific Affairs, LLC, Titusville, NJ, USA. Dr Maio had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of data analysis. The authors have no conflicts of interests relevant to this research. The authors thank Roberto Grilli, MD, and Rossana De Palma, MD, from the Regional Health Care Agency, Emilia-Romagna, Italy, for providing the data and guidance.

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Authors and Affiliations

  1. Jefferson School of Population Health, Thomas Jefferson University, 1015 Walnut Street, Suite 115, Philadelphia, Pennsylvania, 19107, USA

    S. Lane Slabaugh, Vittorio Maio (Associate Professor) & Safiya Abouzaid

  2. Center for Research in Medical Education and Health Care, Jefferson Medical College, Philadelphia, Pennsylvania, USA

    Megan Templin

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  1. S. Lane Slabaugh
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  2. Vittorio Maio
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  4. Safiya Abouzaid
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Correspondence to Vittorio Maio.

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Slabaugh, S.L., Maio, V., Templin, M. et al. Prevalence and Risk of Polypharmacy among the Elderly in an Outpatient Setting. Drugs Aging 27, 1019–1028 (2010). https://doi.org/10.2165/11584990-000000000-00000

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