Long-term cognitive impairment after probable delirium in long-term care residents: A population-based retrospective cohort study

Colleen Webber; Christina Milani; Michael Pugliese; Peter G Lawlor; Shirley H Bush; Christine Watt; Genevieve Casey; Frank Knoefel; Kednapa Thavorn; Franco Momoli; Peter Tanuseputro

doi:10.1111/jgs.18675

Long-term cognitive impairment after probable delirium in long-term care residents: A population-based retrospective cohort study

J Am Geriatr Soc. 2024 Apr;72(4):1183-1190. doi: 10.1111/jgs.18675. Epub 2023 Nov 19.

Authors

Colleen Webber^{1

2

3}, Christina Milani², Michael Pugliese³, Peter G Lawlor^{1

2

4}, Shirley H Bush^{1

2

4}, Christine Watt^{2

4}, Genevieve Casey⁵, Frank Knoefel^{2

6}, Kednapa Thavorn^{1

3

7}, Franco Momoli⁷, Peter Tanuseputro^{1

2

3

4

7}

Affiliations

¹ Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
² Bruyère Research Institute, Ottawa, Ontario, Canada.
³ ICES, Ottawa, Ontario, Canada.
⁴ Department of Medicine, Division of Palliative Care, University of Ottawa, Ottawa, Ontario, Canada.
⁵ Division of Geriatrics, Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
⁶ Department of Family Medicine, University of Ottawa, Ottawa, Ontario, Canada.
⁷ School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada.

PMID: 37982327
DOI: 10.1111/jgs.18675

Abstract

Background: The impact of delirium on cognition has not been well-studied in long-term care (LTC) residents. This study examined changes in cognition 1 year after a probable delirium episode among LTC residents, compared to LTC residents without probable delirium. We also evaluated whether the relationship between probable delirium and cognitive change differed according to a diagnosis of dementia.

Methods: We conducted a population-based retrospective cohort study using linked health administrative data. The study population included adults aged 65+ residing in LTC in Ontario, Canada and assessed via the Resident Assessment Instrument-Minimum Dataset between January 1, 2016 and December 31, 2018. Probable delirium was ascertained via the delirium Clinical Assessment Protocol on the index assessment. Cognition was measured quarterly using the Cognitive Performance Scale (range 0-6, higher values indicate greater impairment). Cognitive decline up to 1 year after index was evaluated using multivariable proportional odds regression models.

Results: Of 92,005 LTC residents, 2816 (3.1%) had probable delirium at index. Residents with probable delirium had an increased odds of cognitive decline compared to those without probable delirium, with adjusted odds ratios of 1.64 (95% confidence interval [CI] 1.35-1.99), 1.56 (95% CI 1.34-1.85), 1.57 (95% CI 1.32-1.86) and 1.50 (95% CI 1.25-1.80) after 1-3, 4-6, 7-9, and 10-12 months of follow-up. Residents with probable delirium and a comorbid dementia diagnosis had the highest adjusted odds of cognitive decline (adjusted odds ratio 5.57, 95% CI 4.79-6.48) compared to those without probable delirium or dementia. Residents with probable delirium were also more likely to die within 1 year than those without probable delirium (52.5% vs. 23.4%).

Conclusions: Probable delirium is associated with increased mortality and worsened cognition in LTC residents that is sustained months after the probable delirium episode. Efforts to prevent delirium in this population may help limit these adverse effects.

Keywords: cognitive decline; delirium; long‐term care.

MeSH terms

Cognitive Dysfunction* / complications
Cognitive Dysfunction* / epidemiology
Delirium* / diagnosis
Dementia* / diagnosis
Humans
Long-Term Care
Ontario / epidemiology
Retrospective Studies

Grants and funding

Bruyere Academic Medical Organization