Environmental Factors Predict the Severity of Delirium Symptoms in Long-Term Care Residents with and without Delirium

Authors

  • Jane McCusker MD, DrPH,

    Corresponding author
    1. Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec
    • St. Mary's Research Centre, St. Mary's Hospital, Montreal, Quebec
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  • Martin G. Cole MD,

    1. St. Mary's Research Centre, St. Mary's Hospital, Montreal, Quebec
    2. Department of Psychiatry, St. Mary's Hospital, Montreal, Quebec
    3. Department of Psychiatry, McGill University, Montreal, Quebec
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  • Philippe Voyer RN, PhD,

    1. Faculty of Nursing Sciences, Laval University, Sainte-Foy, Quebec
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  • Minh Vu MD,

    1. Division of Geriatric Medicine, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec
    2. Department of Medicine, Université de Montréal, Montreal, Quebec
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  • Antonio Ciampi PhD,

    1. St. Mary's Research Centre, St. Mary's Hospital, Montreal, Quebec
    2. Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec
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  • Johanne Monette MD, MSc,

    1. Division of Geriatric Medicine, Jewish General Hospital, Montreal, Quebec
    2. Donald Berman Maimonides Geriatric Center, Montreal, Quebec
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  • Nathalie Champoux MD, MSc,

    1. Institut Universitaire de Gériatrie de Montréal, Montreal, Quebec
    2. Department of Family Medicine, Université de Montréal, Montreal, Quebec, Canada
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  • Eric Belzile MSc,

    1. St. Mary's Research Centre, St. Mary's Hospital, Montreal, Quebec
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  • Alina Dyachenko MSc

    1. St. Mary's Research Centre, St. Mary's Hospital, Montreal, Quebec
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Address correspondence to Dr. Jane McCusker, St. Mary's Research Centre, Hayes Pavilion, Suite 3734, 3830 Avenue Lacombe, Montreal QC H3T 1M5, Canada. E-mail: jane.mccusker@mcgill.ca

Abstract

Objectives

To identify potentially modifiable environmental factors (including number of medications) associated with changes over time in the severity of delirium symptoms and to explore the interactions between these factors and resident baseline vulnerability.

Design

Prospective, observational cohort study.

Setting

Seven long-term care (LTC) facilities.

Participants

Two hundred seventy-two LTC residents aged 65 and older with and without delirium.

Measurements

Weekly assessments (for up to 6 months) of the severity of delirium symptoms using the Delirium Index (DI), environmental risk factors, and number of medications. Baseline vulnerability measures included a diagnosis of dementia and a delirium risk score. Associations between environmental factors, medications, and weekly changes in DI were analyzed using a general linear model with correlated errors.

Results

Six potentially modifiable environmental factors predicted weekly changes in DI (absence of reading glasses, aids to orientation, family member, and glass of water and presence of bed rails and other restraints) as did the prescription of two or more new medications. Residents with dementia appeared to be more sensitive to the effects of these factors.

Conclusion

Six environmental factors and prescription of two or more new medications predicted changes in the severity of delirium symptoms. These risk factors are potentially modifiable through improved LTC clinical practices.

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