Evaluating the Potentials of Biodynamic Lighting for Home Office Workers

Study Overview
=================
Brief Summary
-----------------
This study examines the effectiveness of a biodynamic lighting intervention on the sleep, cognitive functions, and alertness of adults working from home. The biodynamic intervention is an innovative lighting solution that intends to harness both visual and non-visual effects of lighting through delivering varying intensities and spectra during working hours according to a preset protocol.

Detailed Description
-----------------
The practice of working from home was widespread well before the 2020 Covid-19 pandemic; The Covid-19 pandemic pressed the fast-forward button on this trend. One of the biggest business concerns associated with working from home is how to maintain employees' productivity. Lighting has been proven as the main environmental element that significantly impacts office workers' health, sleep, mood, comfort, cognitive functions, and, consequently, productivity. One unintended aspect of working from home is the reduction in light exposure, especially in the contrast between the daytime and evening. The effect of lighting on the office workers, including those working from home, could be roughly divided into two categories: visual route and non-visual route. Both visual and non-visual routes have received significant attention from researchers over the past decade. Yet, current literature lacks research involving a comprehensive approach that systematically evaluates the potential of biodynamic lighting interventions in home workplaces. None of the previous studies have evaluated lighting conditions in the home workplaces nor investigated the effects of lighting interventions on the health and productivity of adults working from home. With the rapid increase in the number of people moving to work from home, special attention should be paid to the lighting condition in home offices and its impacts on these workers. This study examines the effectiveness of a biodynamic lighting intervention on the sleep, cognitive functions, and alertness of adults working from home. The biodynamic intervention is an innovative lighting solution that intends to harness both visual and non-visual effects of lighting through delivering varying intensities and spectra during working hours according to a preset protocol. Additionally, this study aims to compare the homeworkers' lighting conditions, impacts, and daily light exposure and how it is relevant to their sleep pattern and health. The specific aims of this study include: Aim 1: Examine the potential benefits of applying a biodynamic lighting condition in home offices for promoting sleep, cognitive functions, and alertness in remote workers. Aim 2: Objectively explore remote workers' daily light exposure pattern and model its relationship with their sleep quality. Findings from this interdisciplinary study will provide insight into the potential benefits of applying biodynamic lighting in home workplaces for improving health and well-being in remote workers. Findings will also assist the lighting industry in providing necessary lighting technology and products aligned with the uprising trend of working from home.

Official Title
-----------------
Light, Health, and Productivity: Evaluating the Potentials of Biodynamic Lighting for Home Office Workers

Conditions
-----------------
Cognitive Performance, Sleep, Alertness

Intervention / Treatment
-----------------
* Other: Biodynamic
* Other: Active Placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Have an occupation of a dayshift (i.e., occurring between 6 AM and 8 PM) remote office worker, working from home for five days (Monday→Friday) a week with a maximum of 12 hours per day Good health [self-reported medical history] No evidence of sleep disorders [Pittsburgh Sleep Quality Index (PSQI) scores >5 are excluded] No extreme chronotypes (extreme owl or lark) [Morningness-Evningness Questionnaire (MEQ) scores >70 or <30 are excluded; typical bedtime between 8 PM and 2 AM] Normal color vision [as per Ishihara's Tests for Colour Deficiency] No current or planned use of light therapy or light-altering devices (e.g., blue-blocking and/or tinted glasses and contact lenses) No planned upcoming travel during the study participation period Not pregnant Exclusion Criteria: -

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Investigators will examine a series of participants (N=25), each of whom will participate in a five-week experiment. Each participant will have a screening visit at their home. The study will be conducted over five successive one-week periods with two cohorts of participants experiencing the same series of lighting interventions. All data collection will be performed during the working days (Monday - Friday) when participants are exposed to the lighting in their home offices.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Biodynamic Condition followed by an Active Placebo Condition.<br>Each lighting condition will last for two weeks (Weeks 2-3 or 4-5), be limited to the 10 workdays, and be active for 8 hours per day. The order of conditions will be randomized. | Other: Biodynamic<br>* This will be a nine-hour lighting scheme that includes three modes: morning, noon, and afternoon. It mimics natural lighting by providing blue-enriched bright lighting in the morning and yellowish dimmed lighting in the afternoon. The lighting scheme is designed to satisfy the visual lighting needs of office workers while maintaining a robust circadian clock.<br>Other: Active Placebo<br>* We will include an active placebo condition that will be a whole-day lighting scheme with constant color and brightness during working hours. This condition is designed to serve to requirements: (1) to simulate a conventional, well-lit office lighting in compliance with the WELL standard V1 recommendations for circadian lighting design, and (2) to provide an Equivalent Melanopic Lux (EML) equal to the geometric average of EML delivered by the Biodynamic condition. Participants will receive a similar dose of lighting under both the Placebo and Biodynamic conditions; however, the time factor is ignored in the Placebo, and hence the method of delivery is different (constant versus dynamic).<br>|
| Experimental: Active Placebo Condition followed by Biodynamic Condition<br>Each lighting condition will last for two weeks (Weeks 2-3 or 4-5), be limited to the 10 workdays, and be active for 8 hours per day. The order of conditions will be randomized. | Other: Biodynamic<br>* This will be a nine-hour lighting scheme that includes three modes: morning, noon, and afternoon. It mimics natural lighting by providing blue-enriched bright lighting in the morning and yellowish dimmed lighting in the afternoon. The lighting scheme is designed to satisfy the visual lighting needs of office workers while maintaining a robust circadian clock.<br>Other: Active Placebo<br>* We will include an active placebo condition that will be a whole-day lighting scheme with constant color and brightness during working hours. This condition is designed to serve to requirements: (1) to simulate a conventional, well-lit office lighting in compliance with the WELL standard V1 recommendations for circadian lighting design, and (2) to provide an Equivalent Melanopic Lux (EML) equal to the geometric average of EML delivered by the Biodynamic condition. Participants will receive a similar dose of lighting under both the Placebo and Biodynamic conditions; however, the time factor is ignored in the Placebo, and hence the method of delivery is different (constant versus dynamic).<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Nocturnal Sleep Duration (in minutes) as measured by actigraphy | Nocturnal Sleep Duration (in minutes) will be measured by Actigraphy. Longer sleep duration corresponds to improved sleep outcomes. | 24 hours everyday up to week 5 | 
| Change in Percent Sleep Efficiency (total sleep time divided by time in bed) measured by actigraphy | Percent Sleep Efficiency measured by actigraphy. Higher percentage corresponds to higher sleep quality. | 24 hours everyday up to week 5 | 
| Change in the Subjective Sleep quality as measured by a single Likert-like question qualitatively | This is included in the consensus sleep diary and consists of 1 question that is scaled from 1 to 7, with higher score corresponds to poor quality sleep. | everyday up to 5 weeks | 
| Change in working memory as assessed by fractal 2-back score | Fractal 2-back score is based on number of correct responses. Higher test scores indicates better performance of working memory | Once per day, Monday to Friday, during week 1, 3, and 5 | 
| Change in working Memory as assessed by Visual Object Learning Task (VOLT) score | Participants first memorize a set of 3-dimensional Euclidean shapes. During recall, participants are to distinguish between the initial shapes mixed with ten distractor shapes. Score is based on number of correct responses. | Once per day, Monday to Friday, during week 1, 3, and 5 | 
| Change in median reaction time on Psychomotor Vigilance test | Psychomotor vigilance test(PVT) measures alertness and vigilant attention and is considered to be the gold standard measure of neurobehavioral effects of circadian misalignment and sleep loss. A shorter median reaction time corresponds to more attentive state. | Once per day, Monday to Friday, during week 1, 3, and 5 | 
| Change in Balloon Analogue Risk Task (BART) score | Participants inflate balloons of unknown popping probability to obtain the highest reward. Each pump increases the potential reward. The potential reward is lost if the balloon pops. Scores are calculated by adding the number of pumps for unexploded balloons, with higher scores reflecting greater risk-taking. Range varies - explosions are at a random point between 1 and 128 pumps. | Once per day, Monday to Friday, during week 1, 3, and 5 | 
| Change in subjective alertness as assessed by Stanford Sleepiness Scale (SSS) | SSS is a s self-reported Likert-type sleepiness scale which assess mental and physical sedation and sleepiness, respectively, at that moment and time. SSS only consists of 1 question that is scaled from 1 to 7, with 7 being a higher or worse score (i.e. more sleepy and sedated) | Once per day, Monday to Friday, during week 1, 3, and 5 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in motor speed as assessed by Motor Praxis Task | Participants are to quickly touch ever-shrinking boxes. Each time a new box appears in a different location on the screen. A shorter reaction time corresponds to higher sensory motor speed. | Once per day, Monday to Friday, during week 1, 3, and 5 | 
| Change in measure of abstraction: score on abstract matching test | Participants select pairs of shapes that fit with another shape. Higher number of correct responses corresponds to higher measure of abstraction. | Once per day, Monday to Friday, during week 1, 3, and 5 | 
| Change in the spatial orientation: score on line orientation test | Participants are shown two lines at different angles, and are to rotate one line incrementally until it is parallel to the other. Higher scores corresponds to better spatial orientation. | Once per day, Monday to Friday, during week 1, 3, and 5 | 
| Change in complex scanning and visual tracking: score on Digit Symbol Substitution Task (DSST) | Participants touch the number paired to the symbol that matches the current target symbol. Higher score corresponds to better complex scanning and visual tracking capability. | Once per day, Monday to Friday, during week 1, 3, and 5 | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Biodynamic Lighting, Sleep, Remote workers, Cognitive performance, light spectrum