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Original Study
Impact of Polypharmacy on Occurrence of Delirium in Elderly Emergency Patients

https://doi.org/10.1016/j.jamda.2014.08.012Get rights and content

Abstract

Objective

To examine associations between polypharmacy and delirium diagnosed in elderly patients hospitalized in geriatric acute care unit after emergency hospital admission.

Methods

Study design was an observational cohort study in the acute geriatric care unit of a university hospital. We included 410 consecutive patients admitted to the acute geriatric ward during 9 months. Within 72 hours of each patient's hospitalization, a clinically trained geriatrician collected the following data: sociodemographic details (age, sex, type of residence), predisposing factors for delirium, main cause of hospitalization, and current medications. Polypharmacy was defined as 6 or more drugs a day. Delirium was assessed by a geriatrician using the Confusion Assessment Method and was diagnosed on the basis of clinical history with an acute change in usual functional status, behavioral observation, and clinical and cognitive assessment.

Results

Nearly 25% of hospitalized patients had delirium. The Confusion Assessment Method was positive in 69% of patients receiving polypharmacy and in 30% of those not receiving polypharmacy, a relative risk of 2.33. The proportion of elderly patients receiving polypharmacy was 58.53%.

Conclusions

In our study, polypharmacy is an independent risk factor for delirium in a population of elderly patients after emergency admission. In the geriatric population, delirium is an underestimated scourge and because of its medicosocial and economic consequences and its impact on morbidity and mortality, we need to give increased attention to the prevention and control of polypharmacy, which is a predisposing factor for delirium.

Section snippets

Background

Delirium is a major problem for all clinical services providing care for older people. A systematic review that identified 42 studies of occurrence and outcomes of delirium in medical inpatients found that its occurrence varied between 11% and 42%.1, 2 Delirium is characterized by recent onset of fluctuating inattention and drowsiness linked to triggering factors. Its diagnosis rests solely on clinical skills.

Importance

Once a diagnosis of delirium has been established, the potential cause (in particular,

Setting and Participants

We conducted this prospective cohort study in an acute geriatric ward of a university hospital. All patients hospitalized in this unit are admitted via the emergency department and are under the care of geriatricians. Prospective exposed cases were defined as inpatients older than patients 65 years and over taking more than 5 long-term drugs including self-medication and admitted to the acute geriatric ward after an admission in emergency department from January 15, 2010, through October 10,

Results

Four hundred ten patients were included in the study. Their characteristics are summarized in Table 2. The mean age of the overall population was 85.51 years; 24.9% of them lived in nursing homes. The majority were women (64.1%). The mean number of comorbid conditions was 2.41, the majority being cardiovascular diseases followed by dementia. The mean number of long-term medications received was 6.21, of which 1.04 delirium inducing drugs. Two hundred forty patients (58.53%) were receiving

Discussion

Our study showed a significant independent association between the diagnosis of delirium in recently hospitalized elderly patients and polypharmacy. In the 410 patients, the mean number of daily medications was 6.21 (0–18 daily drugs per patient). Explanation of the link between polypharmacy and delirium remains complex. A link between polypharmacy and numerous comorbid conditions has often been reported in the literature, but in our study we found no relation with the number of chronic

References (47)

  • M. Elie et al.

    Delirium risk factors in elderly hospitalized patients

    J Gen Intern Med

    (1998)
  • J.H. Han et al.

    Delirium in the emergency department: An independent predictor of death within 6 months

    Ann Emerg Med

    (2010)
  • E.M. Eeles et al.

    Hospital use, institutionalisation and mortality associated with delirium

    Age Ageing

    (2010)
  • J. Witlox et al.

    Delirium in elderly patients and the risk of postdischarge mortality, institutionalization, and dementia: A meta-analysis

    JAMA

    (2010)
  • J. McCusker et al.

    Does delirium increase hospital stay?

    J Am Geriatr Soc

    (2003)
  • T.G. Fong et al.

    Delirium accelerates cognitive decline in Alzheimer disease

    Neurology

    (2009)
  • T.G. Fong et al.

    Delirium in elderly adults: Diagnosis, prevention and treatment

    Nat Rev Neurol

    (2009)
  • K. Alagiakrishnan et al.

    An approach to drug induced delirium in the elderly

    Postgrad Med J

    (2004)
  • L. Han et al.

    Use of medications with anticholinergic effect predicts clinical severity of delirium symptoms in older medical inpatients

    Arch Intern Med

    (2001)
  • R.Y. Lin et al.

    Drug-induced, dementia-associated and nondementia, non-drug delirium hospitalizations in the United States, 1998–2005: An analysis of the national inpatient sample

    Drugs Aging

    (2010)
  • S.K. Inouye et al.

    Precipiting factors for delirium in hospitalised elderly persons. Predictive model and interrelationship with baseline vulnerability

    JAMA

    (1996)
  • J.T. Hanlon et al.

    Suboptimal prescribing in older inpatients and outpatients

    J Am Geriatr Soc

    (2001)
  • M. Huisman-Baron et al.

    Criteria for drug selection in frail elderly persons

    Drugs Aging

    (2011)

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    The authors declare no conflicts of interest.

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