Development of core outcome sets for effectiveness trials of interventions to prevent and/or treat delirium (Del-COrS): study protocol

Delirium is a common, serious and potentially preventable condition with devastating impact on the quality of life prompting a proliferation of interventional trials. Core outcome sets aim to standardise outcome reporting by identifying outcomes perceived fundamental for measurement in trials of a specific interest area. Our aim is to develop international consensus on two core outcome sets for trials of interventions to prevent and/or treat delirium, irrespective of study population. We aim to identify additional core outcomes specific to the critically ill, acutely hospitalised patients, palliative care and older adults.

Methods and analysis
We will conduct a systematic review of published and ongoing delirium trials (1980 onwards) and one-on-one interviews of patients who have experienced delirium and family members. These data will inform Delphi round 1 of a two-stage consensus process. In round 2, we will provide participants their own response, summarised group responses and those of patient/family participants for rescoring. We will randomise participants to receive feedback as proportion scoring the outcome as critical or as group mean responses. We will hold a consensus meeting using nominal group technique to finalise outcomes for inclusion. We will repeat the Delphi process and consensus meeting to select measures for each core outcome. We will recruit 240 Delphi participants giving us 80% power to detect a 1.0–1.5 point (9-point scale) difference by feedback method between rounds. We will analyse differences for subsequent scores, magnitude of opinion change, items retained and level of agreement.


Louise Rose1,2,3, Meera Agar4, Lisa D Burry5, Noll Campbell6, Mike Clarke7, Jacques Lee8, Najma Siddiqi9, Valerie J Page10 For the Del-COrS group

Author affiliations

1. Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
2. Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, Toronto, Ontario, Canada
3. Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada
4. Faculty of Health Sciences, University of Technology, Sydney, New South Wales, Australia
5. Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
6. College of Pharmacy, Indiana University-Purdue University, Indianapolis, Indiana, USA
7. School of Medicine, Dentistry and Biomedical Sciences, Queen’s University Belfast, Belfast, UK
8. Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
9. School of Medicine, York University, York, UK
10. Department of Anaesthetics, Watford General Hospital, Watford, UK


Journal: BMJ open
Volume: 7
Issue: 9
Pages: -
Year: 2017

Further Study Information

Current Stage: Completed
Funding source(s): The study is funded by the Canadian Institutes of Health Research.

Health Area

Disease Category: Neurology

Disease Name: Delirium

Target Population

Age Range: Unknown


Nature of Intervention:

Stakeholders Involved

Study Type

- COS methods research


Nested methodological studies

We will conduct nested methodological studies to:

1. Determine whether Delphi feedback provided as the proportion of participants scoring the outcome between 7 and 9 (indicating critical for inclusion) as opposed to mean scores influences subsequent scores, magnitude of change, items retained and level of agreement (overall and by patient population group).

2. Qualitatively explore the process of patient/family engagement and participation throughout COS development to determine barriers and facilitators as well as modification of our processes if needed.

3. Determine whether Delphi versus nominal group technique influences which measures are retained for outcomes included in the COS.