Van Rompaey 2012.

Methods	Single‐centre, randomized controlled trial Setting: adult ICU Country: Belgium Groups: Sleeping with earplugs vs. without earplugs Period: November 2008 to April 2009 and November 2009 to April 2010
Participants	Sample size: 136 patients (69/67) Included Adults (≥18 years old) Expected ICU LOS more than 24 hours Speaking Dutch or English Scoring a minimum Glasgow Coma Scale of 10 Excluded Known hearing impairment Dementia Confusion or delirium at admission Sedation (to optimise the assessment of delirium and sleep perception) Missing: number of patients assessed the 1st morning until the 4th morning is stated in the flowchart
Interventions	Intervention: patients slept with ear‐plugs from 10.00 pm to 6.00 am. Control: patients slept without earplugs during the night for a maximum of 5 days
Outcomes	Primary The prevalence of delirium Secondary Self‐reported sleep perception Adverse events: none reported Measured by: the Neelon and Champagne Confusion Scale (NEECHAM) to assess delirium and the Glascow Coma Scale to assess consciousness
Notes	Conclusion: earplugs may be a useful instrument in the prevention of confusion or delirium. The beneficial effects seem to be strongest within 48 hours after admission. More cognitive normal patients were in the intervention group (P = 0.006). There were different observation periods for the two groups: mean observation period in the intervention group was 43 hours opposed to 33 hours in control group. Funding: none stated Conflict of interest: authors stated none Study number: ISRCTN36198138 Contact with author: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Assigned in a 1:1 ratio to intervention or control group using a computer program
Allocation concealment (selection bias)	Low risk	Assignment to the study was done by an independent nurse researcher
Incomplete outcome data (attrition bias) All outcomes	Low risk	Flowchart accounts for all patients throughout the study
Selective reporting (reporting bias)	Low risk	All predefined outcomes stated in the online protocol ISRCTN36198138 were reported
Other bias	Low risk	Low risk of other potential biases
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The researchers were blinded during data collection; patients were not blinded due to study design
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinded researcher assessed patients for delirium and sleep perception

List of acronyms and abbreviations which appear in this table

ADL: activities of daily living; CAM‐ICU: confusion assessment method for the ICU; COPD: chronic obstructive pulmonary disease; CT: computed tomography; DLA: dynamic light application; DSM‐IV: Diagnostic and Statistical Manual of Mental disorders IV; EGDS: early‐goal directed sedation; FDA: Federal Drug Administration;HR: heart rate; ICDSC: Intensive Care Delirium Screening Checklist; ICU: intensive care unit;ITT: intention‐to‐treat; LOS: length of stay; MRI: magnetic resonance imaging; ms: milliseconds; NEECHAM: the Neelon and Champagne confusion scale; NIV: non‐invasive ventilation; PRE‐DELIRIC: PREdiction of DELIRium in ICU patients; QoL: quality of life; RASS: Richmond Agitation and Sedation scale; ROM: range of motion; SAS: Riker Sedation‐Agitation Scale; vs: versus