Shift-work Disorder
Conditions
Brief summary
The purpose of this study is to examine the effectiveness of a personalized light exposure schedule for Shift Work Disorder (SWD) in night shift workers compared to a non-personalized light exposure schedule.
Detailed description
Participants will be randomized into each condition (n = 25) in a 1:1 ratio. Variables of interest, dim light melatonin onset (DLMO) and shift work disorder (SWD) symptoms, will be assessed before and after the intervention, which will last two weeks. All participants (N=50) will be asked to wear an Apple Watch for two weeks leading up to an in-lab visit. Activity data collection from the Apple Watch will be processed through a mathematical model of the human circadian pacemaker (previously validated in SWD) to generate estimates of DLMO. This two-week period is followed by a 27-hour laboratory visit for pre-treatment assessment of DLMO (hourly saliva melatonin samples over 24 hours). At the end of this visit, participants will receive an orientation to the SHIFT mobile application, where they will be able to assess their prescribed light exposure schedule.
Interventions
BEHAVIORALPhototherapy
Light exposure recommendations provided by SHIFT mobile application
Sponsors
American Academy of Sleep Medicine
Henry Ford Health System
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Participants must work at least 2 night shifts a week * Participants must have night shifts starting between 18:00 and 02:00 and lasting 8 to 12 hours * Participants must have maintained this night shift schedule for at least 6 months * Participants must have Shift Work Disorder, diagnosed based on ICSD-3 criteria
Exclusion criteria
* Medical history of central nervous system disorders * Medical history of other sleep disorders * Diagnosis of an unstable major medical condition medical chart review * Dependence on alcohol (≥ 4 beverages a day) * Heavy tobacco use (≥ 10 cigarettes per day) * Recreational drug use * Use of medications impacting central nervous system functioning * Caffeine use in excess of 5-6 servings (\ 600mg) per day * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Dim light melatonin onset | Within two days of treatment for a duration of 24 hours | Melatonin values will be measured in saliva samples, collected in dim light conditions in a laboratory, to determine circadian phase. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Insomnia | Within one week of post-treatment | Insomnia will be measured with the Insomnia Severity Scale (0 to 28; higher scores correspond to worse severity) |
| Daytime sleepiness | Within one week of post-treatment | Sleepiness will be measured with the Epworth Sleepiness Scale (0 to 24; a score of 10 or greater indicates excessive daytime sleepiness) |
Countries
United States
Outcome results
None listed