Article Text

Download PDFPDF

Incidence of delirium in the Canadian emergency department and its consequences on hospital length of stay: a prospective observational multicentre cohort study
  1. Marcel Émond1,2,3,4,5,
  2. Valérie Boucher1,3,4,6,
  3. Pierre-Hugues Carmichael4,
  4. Philippe Voyer1,4,7,
  5. Mathieu Pelletier3,8,
  6. Émilie Gouin9,
  7. Raoul Daoust10,11,
  8. Simon Berthelot1,3,2,
  9. Marie-Eve Lamontagne3,6,
  10. Michèle Morin1,3,
  11. Stéphane Lemire1,3,4,
  12. Thien Tuong Minh Vu12,13,14,
  13. Alexandra Nadeau1,3,4,6,
  14. Marcel Rheault15,
  15. Lucille Juneau16,
  16. Natalie Le Sage1,3,2,
  17. Jacques Lee17,18
  1. 1 Axe Santé des populations et pratiques optimales en santé, Centre de recherche du CHU de Québec-Université Laval, Québec, Canada
  2. 2 Département de médecine d’urgence, CHU de Québec-Université Laval, Québec, Canada
  3. 3 Medicine, Université Laval, Québec, Canada
  4. 4 Centre d’excellence sur le vieillissement de Québec, Québec, Canada
  5. 5 Centre de recherche sur les soins et les services de première ligne de l’Université Laval, Québec, Canada
  6. 6 Centre interdisciplinaire de recherche en réadaptation et intégration sociale, Québec, Canada
  7. 7 Nursing, Université Laval, Québec, Canada
  8. 8 Centre Intégré de Santé et de Services Sociaux de Lanaudière, Joliette, Canada
  9. 9 Centre Hospitalier Régional de Trois-Rivières, Trois-Rivières, Canada
  10. 10 Centre de recherche de l’Hôpital du Sacré-Cœur de Montréal, Montréal, Canada
  11. 11 Medicine, Université de Montréal, Montréal, Canada
  12. 12 Centre de recherche du Centre hospitalier de l’Université de Montréal, Montréal, Canada
  13. 13 Centre hospitalier de l’Université de Montréal, Montréal, Canada
  14. 14 Institut de gériatrie de l’Université de Montréal, Montréal, Canada
  15. 15 CSSS de Trois-Rivières, Trois-Rivières, Canada
  16. 16 Centre Intégré Universitaire de Services Sociaux et de Santé de la Capitale-Nationale, Québec, Canada
  17. 17 Department of Family and Community Medicine, University of Toronto, Toronto, Canada
  18. 18 Sunnybrook Health Sciences Center, Toronto, Canada
  1. Correspondence to Dr Marcel Émond; marcel.emond{at}


Objective We aim to determine the incidence of delirium and describe its impacts on hospital length of stay (LOS) among non-delirious community-dwelling older adults with an 8-hour exposure to the emergency department (ED) environment.

Design This is a prospective observational multicentre cohort study (March–July 2015). Patients were assessed two times per day during their entire ED stay and up to 24 hours on hospital ward.

Setting The study took place in four Canadian EDs.

Participants 338 included patients: (1) aged ≥65 years; (2) who had an ED stay ≥8 hours; (3) were admitted to hospital ward and (4) were independent/semi-independent.

Main outcome(s) and measure(s) The primary outcomes of this study were incident delirium in the ED or within 24 hours of ward admission and ED and hospital LOS. Functional and cognitive status were assessed using validated Older Americans Resources and Services and the modified Telephone Interview for Cognitive Status tools. The Confusion Assessment Method was used to detect incident delirium. Univariate and multivariate analyses were conducted to evaluate outcomes.

Results Mean age was 76.8 (±8.1), 17.7% were aged >85 years old and 48.8% were men. The mean incidence of delirium was 12.1% (n=41). Median IQR ED LOS was 32.4 (24.5–47.9) hours and hospital LOS was 146.6 (75.2–267.8) hours. Adjusted mean hospital LOS was increased by 105.4 hours (4.4 days) (95% CI 25.1 to 162.0, P<0.001) for patients who developed an episode of delirium compared with non-delirious patient.

Conclusions An incident delirium was observed in one of eight independent/semi-independent older adults after an 8-hour ED exposure. An episode of delirium increases hospital LOS by 4 days and therefore has important implications for patients and could contribute to ED overcrowding through a deleterious feedback loop.

  • delirium
  • emergency department
  • community seniors
  • cognitive status
  • functional status

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

View Full Text

Statistics from


  • Contributors MÉ had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. He was responsible for design, funding, conduct of the study and writing of the manuscript. VB managed the study, led the analyses and wrote the manuscript. MÉ, VB and P-HC were involved in the statistical analysis and data interpretation. MP, RD, ÉG and M-EL were responsible for recruitment at all four sites. PV, SB, MM, TTMV, JL, MR, SL, NLS and LJ are all collaborators of INDEED project. P-HC, MP, RD, ÉG, M-EL, PV, SB, MM, TTMV, AN, JL, MR, SL, NLS and LJ reviewed and approved the manuscript.

  • Funding This study was funded by the Fond Québécois de Recherche en Santé (FQRS 29307).

  • Competing interests None declared.

  • Patient consent Obtained.

  • Ethics approval The Comité d'éthique du CHU de Québec acted as the centralised research ethics board and approved this study (project number MP-20-2015-2130).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement Being a prospective observational multicentre study, this project includes other data results to be solely used by our research team. The data use follows the framework governed by a public funding agency (FQRS).

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.