None listed
Conditions
Brief summary
Shift work often leads to poor sleep and wellbeing, fatigue and increased risks of road and workplace accidents. Employees are often impacted differently by shift work and the individual pattern of light exposure plays a crucial role in determining how the body clock responds. There is a need for personalised approaches to the management of sleep and health in shift workers. The project will provide personalised lighting recommendations to shift the timing of worker’s body clocks and help them better adapt to their specific shift work schedules. The strategic light exposure, based on scientific evidence, will target improved sleep, alertness, performance, and wellbeing. Shift workers will participate for up to 8 weeks, depending on their shift schedule. For one shift rotation (first 3 weeks of study), participants will complete short daily questions on sleep and alertness via a smartphone app, and wear a wrist-watch activity monitor and small pendant on their lapel to monitor sleep and light exposure. They will also have their body clock timing measured twice. Based on this monitoring, each participant will be provided with personalised recommendations on when to seek light and when to avoid light during a subsequent shift rotation (last 3 weeks of study). Lighting devices will be provided that suit specific working conditions (e.g., light-emitting glasses or light boxes at work stations). Monitoring of sleep, alertness, light and body clock timing will be repeated to demonstrate the impact of the personalised recommendations.
Interventions
The project will provide workers with personalised recommendations on when to seek light and when to avoid light.
Study duration: up to 8 weeks. Participants will be monitored for 3 weeks at the start and 3 weeks at the end, with a 2-week break in the middle. Participants will follow the lighting recommendations in week 7. The study duration and exact timings/ dates of the recommendations will depend on participants' shift schedule/ rosters.
All data from the initial 3-week monitoring will be
The project will provide workers with personalised recommendations on when to seek light and when to avoid light. Study duration: up to 8 weeks. Participants will be monitored for 3 weeks at the start and 3 weeks at the end, with a 2-week break in the middle. Participants will follow the lighting recommendations in week 7. The study duration and exact timings/ dates of the recommendations will depend on participants' shift schedule/ rosters. All data from the initial 3-week monitoring will be used to personalise the recommendations. This includes participants' habitual sleep (from baseline survey), circadian timing, typical sleep and light exposure, upcoming work roster and personal commitments. The personalised recommendations will be delivered via a handout with written recommendations. The lighting recommendations will start (and finish) 1-2 days before (and after) participants' first (and final) night/ early morning shift for the particular shift rotation. The duration of how long participants follow the recommendations will depend on each participant's roster (e.g., one participant may have 4 consecutive night shifts, whereas another participant has 3 consecutive night shifts). Lighting devices will be provided that suit specific working conditions (e.g., light-emitting glasses - Luminette 3; or light boxes at work stations - HappyLamp). Both device emit light that is up to 10,000 lux and are polychromatic white lights. Participants will be provided with blue-light blocking sunglasses (Block Blue Light: NightFall Wayfarer Blue Blocking Glasses/ NightFall Premium FITOVER Blue Blocking Glasses) to wear after finishing early morning/ night shifts. The duration for which participants will be instructed to use the blue-light blocking sunglasses and light-emitting device will differ for each participant as each intervention is personalised. As an example, one participant may be recommended to: (1) between DATE1 - DATE2, wear the blue-light blocking sunglasses as much as possible from the time of shift completion until going to sleep (but not when driving). (2) Between DATE1-DATE2, use the Luminette device as much as possible when you are on night shifts. (3) Between DATE1-DATE2 on your days off, use the Luminette device between 10am-12pm. Participants will complete daily surveys to self-report the timings of when they used the light-emitting device and blue-light blocking sunglasses.
Sponsors
Monash University
Study design
Allocation
Non-randomised trial
Primary purpose
Treatment
Eligibility
Sex/Gender
All
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
(1) aged 18-65 years, (2) at least 4 night or early morning shifts worked a month on average - with night work defined as at least 6 hours worked between 2200h and 0800h - early morning work defined as starting work before 0700h (3) a roster pattern incorporating at least 3 consecutive night or early morning shifts
Exclusion criteria
Individuals with the following conditions that may impact the main outcomes of the study (internal circadian pacemaker, sleep, or light sensitivity) will be excluded: 1. Have a prior and untreated diagnosis, and/or a current diagnosis of a sleep disorder other than insomnia 2. Are using drugs known to impact sleep, alertness, or the circadian pacemaker (i.e., body clock) 3. Have visual disorders, or history of eye surgery or laser correction 4. Epilepsy, photosensitivity, or have been recommended by a health professional to avoid bright light. 5. Wear prescription glasses with coloured lenses or transition lenses (i.e., lenses that automatically darken in bright light). 6. Report high daytime sleepiness on a short survey (i.e., Epworth Sleepiness Scale score > 16), and typically drive themselves to and from work after early morning/ night shifts
Outcome results
None listed