Colette Fleming
The built environment can have a positive effect on the overall state of a person’s physical and emotional well-being. Nowhere is this more important than in a health-care facility. As Florence Nightingale noted in the 19th century, the physical environment of a medical facility can affect the psychological well-being and behaviour of all occupants—from patients and their visitors to medical staff. Unfortunately, Nightingale’s vision was largely neglected during the post-war economic boom of the mid-20th century when rapid advances in medical technology, and an increased focus on efficiency in the delivery of medical care, meant a decrease in attention on the human dimensions of hospital design. However, just as medicine has moved toward evidence-based [medicine] where clinical choices are informed by studies, health-care design is increasingly guided by rigorous research linking hospitals’ physical environments to patient outcomes.
The contemporary environment of care recognizes that, while the physicality of hospitals must support the effective delivery of care, they are in and of themselves tools in the healing process, supporting wellness through psycho-physiological effects.
Expanded role of lighting
Healthcare organizations and architecture, engineering, and construction (AEC) firms have taken evidence-based design research and expanded it beyond patients with the recognition that the physical environment also affects staff, doctors, and visitors. Many factors are involved in the built environment, including lighting. A growing understanding of the effects of light on human biology, as well as its importance for helping to offer pleasant, non-institutional environments, has created a desire for hospital lighting systems to provide flexibility in spectral output and control. With a focus on both patient and staff wellness, the AEC industry and health-care facility managers are looking for thoughtfully configured lighting that balances both visual and circadian needs and promotes healing outcomes.
Lighting is an important conduit in hospital control systems because it can deliver more connectivity due to its use everywhere. Wireless or wired connectivity with sensors installed in luminaires can provide a continuous stream of data to monitor things. For example, are the rooms occupied, how much natural light is available, or what is the lighting system’s power consumption. With Internet of Things (IoT) functionality, data from lighting systems can be gathered, analyzed, and fed back to facilities professionals. Security, emergency egress and ingress routing, and room light-level control can also be accomplished.
Health-care lighting needs to meet many form-and-function criteria: symbiotic with the overall design, advanced technology that provides multiple precise distribution options to deliver the many layers of light required in health-care environments, lighting that promotes circadian entrainment (i.e. aligning internal body clocks with the 24-hour day), glare-free comfortable lighting that supports the visual tasks of staff while enhancing the overall well-being of patients, and ease of maintenance to withstand harsh cleaning protocols necessary to minimize risk of hospital-acquired infections. This is a tall order. However, advanced technologies, deeper understanding of the varied needs of patients and staff, and forward-thinking manufacturers who have sought end-user input are driving better health-care lighting products and designs.
Importance of glare-free lighting
Glare can simply be annoying, cause discomfort, or diminish one’s ability to perform visual tasks. Depending on an individual’s sensitivity, it may even contribute to eye fatigue and headaches. Different strategies can be used to control glare from lighting. Luminaire design and lighting layout play a significant role as they affect a person’s viewing angle to luminaire brightness. Well-designed optics that uniformly distribute light reduce brightness from luminaires, aiding in visual comfort. Minimizing brightness contrast between luminaires and surrounding ceiling and wall surfaces also reduces impressions of glare, while indirect lighting or localized task lighting can mitigate reflections on computer screens or tablets. There is even a metric used to predict discomfort glare in interior applications. The metric is the unified glare rating (UGR), which factors in several of the elements mentioned here. Providing glare-free comfortable lighting supports the visual tasks of staff while enhancing the overall well-being of patients.
Lighting and patient care
Research shows there is a clear correlation between exposing patients to sufficient light during the day and their improved sleep and mood, and reduced depression and shorter hospital stays. Tunable white technology improves patient outcomes and caregiver well-being by mimicking natural light patterns that support human circadian rhythms. Deviation from an individual’s natural circadian rhythm can negatively affect sleep, appetite, and mood patterns, which, in turn, can affect emotional and physical well-being as well as one’s attentiveness. Forward-thinking lighting manufacturers have developed luminaires to curate these wavelengths that create a balance closer to natural light.
The lighting needs of patients and medical professionals are different. For patients, it is important to create a calm and relaxing environment to which they can easily adjust. However, in examination environments, there is often a need for higher light levels as functional light to support diagnosis and help professionals work more effectively.
In a facility operating 24/7, these conflicting lighting needs, especially during the overnight shift, present a challenge because staff need to be awake and alert at night while patients are resting. To address this, different lighting strategies are needed in patient and staff areas.
Supporting the health of employees
A growing body of evidence is pointing to the disruptive impacts of excessive light exposure at night and its role in circadian misalignment. Approximately one in four health-care workers is engaged in shiftwork, and as a result, has a circadian rhythm that remains permanently out of phase with natural light and dark cycles. Circadian disruption has health consequences in both the short- and long-term. Shift workers are also subject to decreased productivity, alertness, and vigilance, which may contribute to more errors on the job (Read “Designing for Health: Light, Circadian Rhythms, and Health of Caregivers” by Monica Kumar).
There are two ways in which light conditions can support staff wellness with respect to circadian rhythms: adequate exposure to daylight during day hours, and limited or controlled exposure to light at night. By mimicking natural light patterns that support human circadian rhythms, tunable light fixtures can be programmed to subtly change colour temperature and light level throughout the day to help improve patient outcomes and caregiver well-being.
When designing staff zones, consider the activities that take place throughout the day with respect to daylight composition at those times. For instance, if staff are more likely to be in a biologically dark (i.e. non-daylit) space in the morning hours, this increases the importance of trying to simulate daylight through use of fixtures that can provide the right combination of intensity and blue-rich spectrum to support circadian entrainment. During evening hours, consider whether task illuminance thresholds can be met through warm colour temperatures, including amber, and reduced light levels, perhaps through indirect lighting.
Nurses may alternate day and night shifts, and the latter can be rotating or permanent—erratic schedules that easily disrupt circadian rhythms over time. Since adjacent corridor lighting also affects their environment, lighting systems should provide nurses control over spectrum, intensity, and time of day to suit their personal needs and schedule.
