Simons 2016.

Methods	Single‐centre, randomized controlled trial Setting: teaching hospital (730 beds), mixed medical and surgical ICU (16 beds) Country: the Netherlands Groups: High‐intensity dynamic light application (DLA) vs normal lighting Period: July 2011 to 2013
Participants	Sample size: n = 734 (354/ 360) Included ≥18 years of age Expected to stay at least 24 hours Excluded Life expectancy < 48 hours Not assessable for delirium (severe hearing and visual impairment, unable to understand Dutch or severe mental impairment) Missing: 20 excluded (7/13) all accounted for in the flowchart
Interventions	Intervention: for patients in the DLA group lighting level, colour and temperature rose from 7.00 am to 9.00 am. This was maintained to 11.30 am. Until 13.30 pm, lighting was decreased. From 13.30 pm till 16.00 pm, the light was increased again. After 16.00 pm it gradually decreased and lights were switched off automatically at 22.30 pm. Control: standard group was exposed to standard lighting which was turned on and off as usual for procedures
Outcomes	Primary Cumulative incidence of ICU‐acquired delirium, defined as the presence of delirium (at least one positive CAM‐ICU screening) on at least 1 day during the stay in the ICU. Secondary Number of coma‐ and delirium‐free days in 28 days Duration af mechanical ventilation Hospital and ICU LOS ICU and in‐hospital mortality Duration of delirium Delirium was measured by: PREdiction of DELIRium in ICu patients (PRE‐DELIRIC) and CAM‐ICU Adverse events: none reported
Notes	Study was terminated prematurely after an interim analysis for futility. Data were analysed as ITT and per protocol analysis. Conclusion: DLA as a single intervention does not reduce the cumulative incidence of delirium. Bright‐light therapy should be assessed as part of a multicomponent strategy. Funding: none Conflict of interest: none declared Study number: NCT01274819 Contact with authors: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	A 1:1 ratio randomization, according to a secured computer‐generated randomization list
Allocation concealment (selection bias)	Low risk	A secured computer‐generated randomization list was used
Incomplete outcome data (attrition bias) All outcomes	Low risk	Study was well balanced and all patients are accounted for
Selective reporting (reporting bias)	Unclear risk	In the online protocol NCT01274819 it was stated that serum levels of inflammatory markers would be assessed as well as Health‐related Quality of Life 3 and 6 months after discharge; these outcomes were not presented in the paper.
Other bias	Unclear risk	Study was terminated prematurely after an interim analysis for futility. The power calculation suggested that 1000 patients should be included to be able to detect a 10% decrease in the incidence of delirium between groups
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not possible
Blinding of outcome assessment (detection bias) All outcomes	High risk	Outcomes assessment was done by ward nurses who were not blinded