Nowak 2008.

Study characteristics
Methods	Study design: RCT Follow‐up: day 15–19
Participants	Country: USA, Southeastern Michigan Setting: long‐term care facility (unclear number) Inclusion criteria: female medical diagnosis of presumed Alzheimer's disease (mild to severe) inability to sleep through the night and inability to stay awake for daytime activities or meals as reported by staff to occur ≥ 3 times weekly institutionalised in current facility ≥ 6 months medically stable for the last 4 weeks Exclusion criteria: treatment with light within the last 3 months history of photophobia diagnosis of the following: schizophrenia, Parkinson's disease, bipolar disorder, cancer diagnosis receiving treatment, other dementias, macular degeneration, retinitis pigmentosa, diabetic retinopathy, blindness receiving antihistamines, antiemetics, corticosteroids, dopaminergics, lithium, sedative hypnotics Number of participants completing the study: 20 (IG 10, CG 10) Baseline characteristics: age (years, mean): 85.9 (SD 6.24) 18 (90%) Caucasian MMSE (mean): 1.95 (SD 2.86) 18 (90%) widowed length of stay in the care facility (months, mean): 30.85 (SD 18.22) 16 (80%) had 1 roommate 7 (35%) in assisted living and 13 (65%) in long‐term care. Group differences: none for sleep measures (others not reported)
Interventions	Intervention: blue–green light exposure to 12,000 lux for 30 minutes between 6 a.m. and 7 a.m. for 14 consecutive days via cap visors. Control: dim red light exposure to 5 lux for 30 minutes between 6 a.m. and 7 a.m. for 14 consecutive days via cap visors.
Outcomes	Sleep efficiency (actigraphy) Sleep fragmentation (actigraphy) Excessive daytime sleep (Stanford Sleepiness Scale)
Funding	Dissertation award from Graduate School College of Nursing at Wayne State University
Notes	PhD thesis
Risk of bias
Bias	Authors' judgement	Support for judgement
Sequence generation	Unclear risk	Quote: "… randomized to either the experimental condition or control group utilizing a five‐block randomized block design (Appendix F)" (p.54).
Allocation concealment	Unclear risk	Not reported.
Blinding of participants and personnel All outcomes	Unclear risk	All interventions and outcome assessment actions were performed by the principal investigator.
Blinding of participants and personnel Subjective sleep quality (carer ratings)	High risk	Quote: (post‐test and follow‐up) "The SSS was completed by the PI [principal investigator] as noted in Phase 2 three times per day (at meal times) for five consecutive days beginning on day 1 of the follow‐up period." (by telephone or by direct observation) (p.56/57). Unblinded staff assessed the outcomes.
Blinding of participants and personnel Objective sleep measures	Low risk	Actigraphy.
Blinding of outcome assessors Objective outcome measures	Low risk	Actigraphy.
Blinding of outcome assessors Subjective sleep quality (carer ratings)	High risk	Quote: (post‐test and follow‐up) "The SSS was completed by the PI as noted in Phase 2 three times per day (at meal times) for five consecutive days beginning on day 1 of the follow‐up period" (by telephone or by direct observation) (p.56/57). Unblinded staff assessed these outcomes.
Incomplete outcome data All outcomes	Low risk	Dropout rate: 1/21 (p.105).
Selective outcome reporting	Unclear risk	Study was not registered and no protocol was published.
Other sources of bias	Low risk	None.