Patient characteristics associated with polypharmacy and inappropriate prescribing of medications among older adults with cancer

https://doi.org/10.1016/j.jgo.2012.02.005Get rights and content

Abstract

Objectives

To identify patient characteristics associated with polypharmacy and inappropriate medication (PIM) use among older patients with newly diagnosed cancer.

Materials and Methods

This is a cross-sectional study conducted in ambulatory oncology clinics at an academic center. Participants included 117 patients aged ≥ 65 years with newly diagnosed histologically confirmed stage I–IV cancer and were enrolled between April 2008 and September 2009. Medication review, included patient self-report and medical records. Polypharmacy was defined as the concurrent use of ≥ five medications, (Yes/No). PIM use was defined as use of ≥ one medication included in the 2003 update of Beers Criteria, (Yes/No).

Results

The prevalence of polypharmacy and PIM use was 80% and 41%, respectively. Three independent correlates of medication use were identified. An increase in comorbidity count by one, ECOG-PS score by one, and PIM use by one, was associated with an increase in medication use by 0.48 (P = 0.0002), 0.79 (P = 0.01) and 1.22 (P = 0.006), respectively. Two independent correlates of PIM use were identified. The odds of using PIMs decreased by 10% for one unit increase in Body Mass Index [Odds Ratio (OR) 0.90, 95% CI = (0.84, 0.97)], and increased by 18% for each increase in medication count by one [OR 1.18, 95% CI = (1.04, 1.34)].

Conclusion

There was a high prevalence of polypharmacy and PIM use in older patients with newly diagnosed cancer. Given the co-occurrence of polypharmacy with poor performance status and multi-morbidity, multi-dimensional interventions are needed in the geriatric-oncology population to improve health and cancer outcomes.

Introduction

In the aging population, polypharmacy and potentially inappropriate prescribing of medication (PIM) is highly prevalent.[1], [2], [3], [4], [5], [6], [7], [8] Polypharmacy has been associated with an increased risk of PIM[1], [5], [6], [9], [10] and increased risk of adverse drug events (ADEs), and may increase the risk of falls and geriatric syndromes as well as morbidity and mortality in the elderly population.[6], [11], [12], [13]

Oncology patients are often on complex medication regimens, and receive medications not only to treat their malignancy and comorbidities, but also to treat therapy-induced toxicity and conditions related to their malignancy such as deep vein thrombosis and seizures.[5], [14], [15], [16] Oncology patients are also seen by multiple physicians, including an oncologist and a primary care physician, who could prescribe multiple different medications for the same symptoms.[5], [17] Compounding the issue of polypharmacy in oncology patients is the use of herbal medications, as prior data has shown that at least one-third of cancer patients use at least one alternative medication.[16], [18] As such, polypharmacy may be more prevalent in older cancer patients. These medications can interact with the patient's regular medication regimen as well as traditional cancer therapies, causing ADEs.[16], [17], [18] Finally, the risk of drug interactions increases with the addition of each antineoplastic agent, placing the patient at risk for further ADEs.[17], [19]

The Beers Criteria were developed from expert consensus to identify potentially inappropriate medications in the elderly population that should be avoided.[2], [3], [4], [20] These criteria include drugs with a long half-life, medications with side effects such as sedation or anticholinergic effects, medications that are high risk when safer alternatives exist or are ineffective, doses of drugs that should not be exceeded, and drug–disease and drug–drug interactions that should be avoided in the elderly populations.[1], [2], [3], [4] The prevalence of PIM use ranges from 33% to 37% of acutely ill patients presenting to hospitals, 28% of elderly community-dwelling residents, 49% of elderly patients presenting to the outpatient primary care clinic and in up to 40% of nursing home residents.[1], [2], [8], [21], [22], [23], [24] Use of Beers Criteria Medications among older patients is associated with increased rate of outpatient visits, reduced time to hospitalization, increased frequency of emergency department visits, increased healthcare costs, and increased mortality.[5], [7], [9], [21] Use of PIMs has been shown to be associated with polypharmacy and with ADEs.[25], [26]

However, few original studies have examined the presence of polypharmacy and inappropriate prescribing of medications in older cancer patients.[14], [15], [27] The objective of this study, therefore, was to examine the prevalence of polypharmacy and the inappropriate prescribing of medications, and to determine factors independently associated with polypharmacy and PIM use among older patients with newly diagnosed cancer.

Section snippets

Study Design and Patient Population

This is a baseline cross-sectional study nested within a longitudinal study of older cancer patients ≥ 65 years of age with histologically confirmed new cancer diagnosis, irrespective of stage at diagnosis. Participants were recruited from ambulatory oncology clinics at an academic center between February 1, 2008 and September 30, 2009. Participants who had received any prior chemotherapy or radiation therapy for current cancer, were unable to give informed consent or were non-English speaking

Participants' Baseline Characteristics

117 patients were enrolled into this study with a mean age of 74.6 years (SD = 6.9). Table 2 displays the distribution of baseline characteristics. The majority of the participants (56%) were between the ages of 65 and 74 years. The study population consisted predominantly of white Medicare-insured patients, about half of whom had more than a high school education (45%), were other than married (65%), and lived alone (42%). Most participants had breast cancer (59%), stage I–II disease (59%), and

Discussion

In this cohort of patients, 65 years and older, with newly diagnosed cancer we found a very high prevalence of polypharmacy, and sometimes, medications being used were inappropriate. Participants with multiple comorbidities, sub-optimal performance status and on inappropriate medications were most likely to be on five or more concurrent medications. Factors associated with inappropriate medication use included having multiple comorbidities and being underweight.

The average use of 7.3 medications

Disclosures

Sponsor's role: The sponsors did not play any role in the design or conduct of the study; collection, management, analysis, or interpretation of the data; or preparation, review, or approval of the manuscript.

Disclaimer: The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Author Contributions

Conception design: Cynthia Owusu.

Acquisition of data: Cynthia Owusu, Gopi Prithviraj, Rakesh Bagai.

Analysis and interpretation of data: Cynthia Owusu, Gopi Prithviraj, Siran Koroukian, Seunghee Margevicius, Rakesh Bagai, Nathan Berger.

Manuscript writing and approval: Cynthia Owusu, Gopi Prithviraj, Siran Koroukian, Seunghee Margevicius, Rakesh Bagai, Nathan Berger.

Conflict of Interest Statement

The authors have no conflicts of interest to disclose.

Acknowledgments

Funding sources: This study was supported in part by the Cancer Aging Research Program Development Grant (P20 CA103767, Nathan Berger, M.D., Principal Investigator: Cynthia Owusu, M.D., Pilot Project Recipient) and by the Clinical Oncology Research Career Development from the National Cancer Institute (2K12 CA076917-11, Stanton Gerson, M.D., Principal Investigator: Cynthia Owusu, M.D., Paul Calabresi Scholar).

Abstract presentation: Prithviraj G. K., Bagai R, Koroukian S, Berger N, Owusu C:

References (46)

  • M.H. Beers et al.

    Explicit criteria for determining inappropriate medication use in nursing home residents. UCLA Division of Geriatric Medicine

    Arch Intern Med

    (1991 Sep)
  • S.M. Lichtman et al.

    Anticancer drug therapy in the older cancer patient: pharmacology and polypharmacy

    Curr Treat Options Oncol

    (2008 Jun)
  • D.T. Lau et al.

    Hospitalization and death associated with potentially inappropriate medication prescriptions among elderly nursing home residents

    Arch Intern Med

    (2005 Jan 10)
  • H.J. Hamilton et al.

    Inappropriate prescribing and adverse drug events in older people

    BMC Geriatr

    (2009)
  • C. Ryan et al.

    Appropriate prescribing in the elderly: an investigation of two screening tools, Beers criteria considering diagnosis and independent of diagnosis and improved prescribing in the elderly tool to identify inappropriate use of medicines in the elderly in primary care in Ireland

    J Clin Pharm Ther

    (2009 Aug)
  • J.T. Hanlon et al.

    Impact of inappropriate drug use on mortality and functional status in representative community dwelling elders

    Med Care

    (2002 Feb)
  • J.V. Agostini et al.

    The relationship between number of medications and weight loss or impaired balance in older adults

    J Am Geriatr Soc

    (2004 Oct)
  • D.K. Weiner et al.

    Effects of central nervous system polypharmacy on falls liability in community-dwelling elderly

    Gerontology

    (1998)
  • T.S. Field et al.

    Risk factors for adverse drug events among nursing home residents

    Arch Intern Med

    (2001 Jul 9)
  • R.P. Riechelmann et al.

    Potential drug interactions and duplicate prescriptions among cancer patients

    J Natl Cancer Inst

    (2007 Apr 18)
  • R.J. Maggiore et al.

    Polypharmacy in older adults with cancer

    Oncologist

    (2010)
  • J. Tam-McDevitt

    Polypharmacy, aging, and cancer

    Oncology

    (2008 Aug;22)
  • D. Misra et al.

    Aging and cancer

    Clin Adv Hematol Oncol

    (2004 Jul)
  • Cited by (118)

    View all citing articles on Scopus
    View full text