Bragard 2013.

Methods	Randomised controlled trial with cross‐over design and individual allocation. Comparison: individually applied blue‐enriched light vs no treatment. Participants allocated into 2 blocks: ABAB and BABA, where 2 × 4‐week periods of using intervention A were alternated with 2 × 4‐week periods of not using (intervention B).
Participants	Staff members (secretaries, nurses, doctors, psychologists, physicians) working in a hospital with no access to natural light; n = 25. Only 25% of the staff participated in the study. Mean (SD) age 36.6 ± 7.7 years.
Interventions	Intervention A: blue‐enriched light emitted by 8 LEDs mounted in spectacles (Luminette), which were directed on the lower part of the retina. Participants used Luminette at work between 07:00 a.m. and 09:00 a.m. for a maximum of 30 minutes a day, at least 5 days a week. Intervention B: no treatment.
Outcomes	Alertness assessed using Epworth Sleepiness Scale. Mood assessed and reported using Beck Depression Inventory‐II.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Comment: randomisation performed by random draw.
Allocation concealment (selection bias)	Unclear risk	Comment: methods for allocation concealment not reported.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: intervention compared to no treatment.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment: outcomes derived from questionnaires answered by participants not blind for interventions.
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "Fourteen employees participated in all assessment phases. No significant scoring difference was noted at time in the questionnaires between subjects who continued (n = 14) and those who stopped (n = 11). Reasons for stopping the use of Luminette® were multiple: negative side effects (e.g. migraines, nausea), decreased interest in the study, exclusion of pregnant women, and holidays (including Christmas)." Comment: only 14/25 participants finished study protocol. Reasons not fully reported. High rate of attrition (44%). Unclear if there was imbalance between groups regarding number of losses and reasons for dropping out.
Selective reporting (reporting bias)	High risk	Comment: data from SIGH‐HDRS, planned in Methods section, was not reported.
Other bias	Low risk	Comment: no other bias identified.
Carry‐over effect	Unclear risk	Comment: carry‐over effect could not be ruled out.
Availability of 2‐period data	Low risk	Comment: data reported from first and second intervention period and for first control period.
Incorrect analysis	Low risk	Comment: paired analyses presented.
Comparability of results with those from parallel‐group trials	Unclear risk	Comment: no results from parallel‐group trials available for same intervention.