Lighting the Way to Fall Prevention in Older Adults

By Mariana G. FigueiroI, David Pedler and Daniel Frering, Light and Health Research Center (LHRC) at Mount Sinai.

In 2008, LHRC researchers proposed a 24-hour lighting scheme for positively impacting the visual, circadian, and perceptual systems of older adults.(1) Incorporating lighting principles that considered the needs of the aging eye, the scheme included delivering a robust light-dark pattern to promote circadian entrainment and better sleep. We also proposed the innovative use of horizontal and vertical doorframe lights to provide visual cues for helping with postural control and stability, which become compromised as we age.

A recommended practice (ANSI/IES RP28-20) addressing lighting for older adults already exists.(2) We know that the aging eye needs greater amounts of light to see fine details, is more sensitive to glare, and takes longer to adapt to changes in the lighted environment. Moreover, sleep disturbances and falls that can result from poor lighting conditions pose major health risks for older adults living at home or in more controlled environments like assisted living centers and nursing homes.

Our research team has been testing the impact of a tailored lighting intervention (TLI) delivering high circadian stimulus (CS) during the day, complemented by low CS in the evening, on measures of sleep, mood, and behavior in dementia patients living in controlled environments.(3-5) More recently, we have replicated these remarkable findings in additional nursing homes. (6,7)

Figure 1. Rendering of the LHRC’s doorframe lighting system for reducing nighttime falls among older adults. The outer arrows mark the vertical and horizontal visual cues provided by the doorframe lights.

This contribution describes our latest work in the development, testing, and implementation of a novel lighting system designed to prevent falls, which have emerged as the leading cause of injury and death among older adults in the U.S.

Figure 2. In one experiment, subjects were exposed to ambient light (AL) from a ceiling luminaires (≈ 650 lx at the cornea), plugin nightlights (NL), and the doorframe lighting (DfL) over three sessions. Their weight transfer time (WTT), which gauges difficulty experienced when rising from a seated position, was measured for each lighting condition. Among those with a history of falling, as shown here, the DfL condition produced the shortest WTT (least difficulty) and the NL condition produced the longest WTT (greatest difficulty). The statistically significant differences between the conditions for the “faller” subjects are represented above the arrows.

An Innovative Lighting Solution

The design challenge, as we see it, is essentially twofold. First, a fall-prevention lighting system must consider the physiological and biomechanical mechanisms involved in balance and postural stability, falls, and aging. Second, because a light stimulus received at any time evokes an alerting response in humans of all ages, the light must be delivered at sufficiently low levels to avoid disrupting nighttime sleep. This latter factor is especially important when it comes to older adults, many of whom experience nighttime sleep disturbances.(8) The incidence of sleep problems is reported to increase dramatically among those with Alzheimer’s disease and Lewy body or Parkinson’s disease dementia.(9)

Balance and postural stability are essential elements for avoiding falls. But those elements are governed by several interconnected body systems (e.g., sensory, musculoskeletal, neuromuscular, vestibular, and cognitive) that deteriorate as we age. The aging eye, for example, can experience reductions in nighttime vision that inhibit our ability to perceive obstacles in darkened spaces. Age-related cognitive decline can adversely affect awareness of our surroundings and compromise our ability to plan and navigate nighttime routes to the bathroom or the kitchen.

The LHRC’s past research has demonstrated that a lighting system providing vertical and horizontal visual cues via diffuse low-level illumination around a doorframe (Figure 1) can effectively help to prevent falls in older adults without delivering an incidental alerting effect.(10,11) The doorframe lighting system reduced sway; improved postural stability, spatial orientation, and balance (Figure 2); and made nighttime navigation safer for older adults without compromising their sleep quality.

A very recent (but not yet published) clinical trial study conducted by researchers from the LHRC and the University of North Carolina (UNC) demonstrated that, compared to conventional plug-in nightlights, a simple doorframe lighting system (fabricated in the LHRC lab) contributed to a 34% reduction in falls among older adults with Alzheimer’s disease and related dementias living in long-term care facilities. Only one of the study’s 38 participants was reported to have experienced greater difficulty falling asleep and none were reported to have been disturbed by the lights while asleep.

In a follow up, multi-year, multi-million-dollar project funded by the National Institute on Aging, we are continuing our collaboration with UNC and extending the research to over 300 rooms in various independent and assisted living facilities in North Carolina. Stay tuned for the exciting results!

What Else Is in Store?

Given what’s at stake and the tantalizing prospect of delivering a relatively low-tech, decidedly low-cost, yet effective intervention for reducing nighttime falls in this vulnerable population, the time is now to bridge the gap between laboratory research and real-world practice in the homes of older adults. To date, only a single manufacturer has developed a similar system for new-build and retrofit architectural applications. But this situation is about to change with the upcoming introduction of a commercially available, competitively priced (around $50 US) DIY-friendly doorframe lighting system that requires only simple tools for installation and an available electrical outlet.

LHRC researchers hope soon to embark on a groundbreaking project that will see this new product furnished in 40 low-income residences visited by home healthcare providers for older adults. The intervention will be evaluated in terms of reductions in patient falls, fear of falling, effects on sleep onset and sleep quality, ease and frequency of use, and overall level of satisfaction with the device.

We are optimistic that this research will pave the way for tangible improvements in quality of life and thereby support low-income adults’ continued ability to live safely and independently in their homes. Should the project’s results prove beneficial and practical on a larger scale, we also expect that the intervention will reduce older adults’ healthcare costs and lead to a positive return on investment in preventative care for agencies providing healthcare services for older adults.

In the 15 years since we first published our proposed 24-hour lighting scheme for older adults, we have come full circle: proposing the idea, lab and field testing the system, and working with industry to develop products and make them available in the market. The next step is for designers to implement it!

References

1. Figueiro MG, Saldo E, Rea MS, Kubarek K, Cunningham J, Rea MS. Developing architectural lighting designs to improve sleep in older adults. The Open Sleep Journal 2008; 1: 40-51.

2. Illuminating Engineering Society. Lighting and the Visual Environment for Older Adults and the Visually Impaired. Standard ANSI/ IES RP-28-20. New York: Illuminating Engineering Society, 2020.

3. Figueiro MG, Plitnick BA, Lok A, Jones GE, Higgins P, Hornick TR, Rea MS. Tailored lighting intervention improves measures of sleep, depression, and agitation in persons with Alzheimer's disease and related dementia living in long-term care facilities. Clinical Interventions in Aging 2014; 9: 1527-1537.

4. Figueiro MG, Plitnick B, Roohan C, Sahin L, Kalsher M, Rea MS. Effects of a tailored lighting intervention on sleep quality, rest–activity, mood, and behavior in older adults with Alzheimer’s disease and related dementias: A randomized clinical trial. Journal of Clinical Sleep Medicine 2019; 15: 1757-1767.

5. Figueiro MG, Sahin L, Kalsher M, Plitnick B, Rea MS. Long-term, all-day exposure to circadian-effective light improves sleep, mood, and behavior in persons with dementia. Journal of Alzheimer's Disease Reports 2020; 4: 297-312.

6. Figueiro MG, Pedler D. Be creative! Three approaches to a tailored lighting intervention for improving sleep-wake cycles in dementia patients. designing lighting. Brentwood, TN: EdisonReport, 20233, p. 20-22.

7. Figueiro MG, Pedler D, Plitnick B, Zecena E, Leahy S. Tailored lighting intervention (TLI) for improving sleep-wake cycles in older adults living with dementia. Frontiers in Physiology 2023; 14: 1290678.

8. Gordon NP, Yao JH, Brickner LA, Lo JC. Prevalence of sleep-related problems and risks in a community-dwelling older adult population: A cross-sectional survey-based study. BMC Public Health 2022; 22: 2045.

9. Wong R, Lovier MA. Sleep disturbances and dementia risk in older adults: Findings from 10 years of national U.S. prospective data. American Journal of Preventive Medicine 2023; 64: 781-787.

10. Figueiro MG, Gras LZ, Rea MS, Plitnick B, Rea MS. Lighting for improving balance in older adults with and without risk for falls. Age and Ageing 2012; 41: 392-5.

11. Figueiro MG, Plitnick B, Rea MS, Gras LZ, Rea MS. Lighting and perceptual cues: Effects on gait measures of older adults at high and low risk for falls. BMC Geriatrics 2011; 11: 49.