The effect of personalised lighting recommendations on sleep and alertness in shift workers

Not Applicable

• Conditions: Sleep loss; Sleepiness; Shift Work; Circadian Misalignment; Public Health - Health promotion/education; Neurological - Other neurological disorders; Mental Health - Other mental health disorders

• Registration Number: ACTRN12622000833763
• Lead Sponsor: Monash University

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2022-06-14
• Last Update Posted: 20 June 2022

Recruitment & Eligibility

• Status: ot yet recruiting
• Sex: All
• Target Recruitment: 100

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

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Circadian timing (concentration of 6-hydroxymelatonin sulfate (aMT6) in urine samples across the 48-hour collection)[Circadian timing is assessed pre-intervention and during the intervention:<br>(1) 2 x 48-hour urine collection during shift rotation at baseline (pre-intervention)<br>(2) 2 x 48-hour urine collection during shift rotation during the intervention (week 5 and week 7 of the 8-week study)];Sleep duration and quality will be measured using actigraphy and daily sleep diaries (adapted from Consensus Sleep Diary). A composite primary outcome will be generated by using sleep diaries to confirm actigraphy sleep and wake timings.[Monitored daily during shift rotation over a period of up to 3 weeks at baseline (pre-intervention), and during the subsequent shift rotation over a period of up to 3 weeks post-intervention commencement,];Sleepiness (Karolinska Sleepiness Scale)[Completed 3 times for every shift:<br>1) Start of shift<br>2) Middle of shift<br>3) End of work shift<br>]

Secondary Outcome Measures

Name	Time	Method
Depression, Anxiety and Stress Scale - 21 Items (DASS-21)[Baseline and End-of-study (at the completion of the shift rotation up to 3 weeks post-intervention/ last week of study)];Insomnia Severity Index[Baseline and End-of-study (at the completion of the shift rotation up to 3 weeks post-intervention/ last week of study)];Daily patterns of light exposure (measured via a light pendant (ActTrust, model code AT0503LF, Condor Instruments, Brazil).[Monitored daily during shift rotation over a period of up to 3 weeks at baseline (pre-intervention), and during the subsequent shift rotation over a period of up to 3 weeks post-intervention commencement,];Daily sleepiness when driving to and from work (Karolinska Sleepiness Scale, completed before and after every drive).[Monitored daily during shift rotation over a period of up to 3 weeks at baseline (pre-intervention), and during the subsequent shift rotation over a period of up to 3 weeks post-intervention commencement,]