Condition category
Mental and Behavioural Disorders
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Delirium is a state of mental confusion that can happen if you become medically unwell. It is a common complication in the intensive care unit (ICU). The aim of this study is to find out whether delirium can be prevented in ICU patients by using earplugs at night.

Who can participate?
Adult patients staying for at least one night in the intensive care department of the Antwerp University Hospital.

What does the study involve?
Participants are randomly allocated either to wear earplugs overnight or to not wear earplugs overnight. Delirium and sleep quality are assessed on the following morning.

What are the possible benefits and risks of participating?
The intervention did not interfere with the treatment or standard ICU care. No risks were expected.

Where is the study run from?
University of Antwerp (Belgium).

When is the study starting and how long is it expected to run for?
November 2008 to April 2010.

Who is funding the study?
University of Antwerp (Belgium).

Who is the main contact?
1. Prof dr P Jorens
2. Prof dr B Van Rompaey (

Trial website

Contact information



Primary contact

Prof Bart Van Rompaey


Contact details

Universiteitsplein 1
Gebouw R 3.30

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

The effect of earplugs during the night on the onset of delirium and sleep perception in intensive care patients: an observational study


Study hypothesis

Sleeping with earplugs during the night lowers the prevalence of delirium and confusion in intensive care patients. Also, sleep perception will improve.

Ethics approval

Ethical board of the Antwerp University hospital, November 2008, ref: 8/40/223

Study design

Single-center observational randomized clinical trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Delirium in intensive care patients


The researchers screened all intensive care patients on a daily basis to invite eligible patients to the study. After giving informed consent, an independent nurse researcher assigned the patients to the study group or the control group. Next, a nontransparent canister holding earplugs or a dummy was positioned at the bedside of the patient. Tthe critical care nurse opened the cannister at 22.00 hr and positioned the earplugs when present. A second assignment at 06.00 hr asked the critical care nurse to remove the earplugs from the patient and to keep them in the closed canister again. When the canister contained a dummy instead of earplugs, no action was undertaken. Patients and staff were instructed not to report on wearing earplugs or not during the night to the researchers. One of the blinded researchers visited the patients during the morning to assess them for delirium and sleep perception.

Intervention type



Not Applicable

Drug names

Primary outcome measures

1. Delirium was assessed using the Neelon and Champagne Confusion Scale (NEECHAM)
1.1. The NEECHAM is based on the nurses' twenty-four hour assessment of the level of processing information, the level of behavior and the physiological condition rating the patient on a 30-0 scale. Next, the results can be classified in one of four categories. The cut-off values, 30-27 'normal', 26-25 'at risk', 24-20 'early to mild confusion' (mild confusion) were standardized. The scores 19-0 'moderate to severe confusion' show delirium in the studied patient.
2. Sleep perception was assessed using five dichotomous questions on the self reported sleep quality of the patient:
2.1. Did you sleep well?
2.2. Did you sleep better as expected?
2.3. Did you sleep better than at home?
2.4. Were you awake for a long time before falling asleep?
2.5. Do you feel sufficiently rested? The score on question four was reversed. A higher total sum score on the five questions showed a better sleep perception.

Secondary outcome measures

No secondary outcome measures

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Adult (18 year or older)
2. The expected length of stay in the intensive care unit (ICU) was over 24 hours
3. Dutch or English speaking
4. Scoring a minimum Glasgow Coma Scale of 10

Participant type


Age group




Target number of participants

When the use of earplugs could lower the incidence of 'delirium or confusion' with 20%, a power of 0.80 and á=0.05 showed that 46 patients in each group had to be included

Participant exclusion criteria

1. Patients with known hearing impairment
2. Dementia
3. Confusion or delirium at admittance
4. Also, sedation was used as a exclusion criterion to optimize the assessment of delirium and sleep perception

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

University of Antwerp

Sponsor information


University of Antwerp (Belgium)

Sponsor details

Faculty of Medicine and Healthcare
Division of Nursing Science and Midwifery
Universiteitsplein 1

Sponsor type




Funder type


Funder name

University of Antwerp (Belgium)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2012 results in:

Publication citations

Additional files

Editorial Notes