Environmental (little outdoor light; low indoor lighting) and age-related physiological factors (reduced light transmission through the ocular lens, reduced mobility) contribute to a light-deprived environment for older people living in care homes. This study investigates the effect of increasing indoor light levels with blue-enriched white lighting on objective (rest-activity rhythms, performance) and self-reported (mood, sleep, alertness) measures in older people. Eighty residents (69 female), aged 86 ± 8 yrs (mean ± SD), participated (MMSE 19 ± 6). Overhead fluorescent lighting was installed in communal rooms (n=20) of seven care homes. Four weeks of blue-enriched white lighting (17000 K 900 lux) were compared with four weeks of control white lighting (4000 K 200 lux), separated by three weeks wash-out. Participants completed validated mood and sleep questionnaires, psychomotor vigilance task (PVT) and wore activity and light monitors (AWL). Rest-activity rhythms were assessed by cosinor, non-parametric circadian rhythm (NPCRA) and actigraphic sleep analysis. Blue-enriched (17000 K) light increased wake time and activity during sleep decreasing actual sleep time, sleep percentage and sleep efficiency (p < 0.05) (actigraphic sleep). Compared to 4000 K lighting, blue-enriched 17000 K lighting significantly (p < 0.05) advanced the timing of participants' rest-activity rhythm (cosinor), increased daytime and night-time activity (NPCRA), reduced subjective anxiety (HADA) and sleep quality (PSQI). There was no difference between the two light conditions in daytime alertness and performance (PVT). Blue-enriched lighting produced some positive (increased daytime activity, reduced anxiety) and negative (increased night-time activity, reduced sleep efficiency and quality) effects in older people.
This research output has an Altmetric Attention Score of 31. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 25 March 2025.
All research outputs
#1,633,772
of 34,411,289 outputs
Outputs from Current Alzheimer Research
#37
of 1,453 outputs
Outputs of similar age
#25,121
of 462,789 outputs
Outputs of similar age from Current Alzheimer Research
#3
of 107 outputs
Altmetric has tracked 34,411,289 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 95th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 1,453 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 10.1. This one has done particularly well, scoring higher than 97% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 462,789 tracked outputs that were published within six weeks on either side of this one in any source. This one has done particularly well, scoring higher than 94% of its contemporaries.
We're also able to compare this research output to 107 others from the same source and published within six weeks on either side of this one. This one has done particularly well, scoring higher than 97% of its contemporaries.
