Use of Consumer Sleep Technology to Treat Shift Work Disorder

Study Overview
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Brief Summary
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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
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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.

Official Title
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Innovations in Wearable Technology for Correcting Circadian Misalignment in Shift Work Disorder

Conditions
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Shift-work Disorder

Intervention / Treatment
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* Behavioral: Phototherapy


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Non-personalized light condition<br>Participants will receive light exposure recommendations from the SHIFT mobile application based on their habitual sleep schedule. Participants will follow these recommendations over the course of two weeks. | Behavioral: Phototherapy<br>* Light exposure recommendations provided by SHIFT mobile application<br>|
| Experimental: Personalized light condition<br>Participants will receive light exposure recommendations from the SHIFT mobile application based on their activity levels. Participants will follow these recommendations over the course of two weeks. | Behavioral: Phototherapy<br>* Light exposure recommendations provided by SHIFT mobile application<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dim light melatonin onset | Melatonin values will be measured in saliva samples, collected in dim light conditions in a laboratory, to determine circadian phase. | Within two days of treatment for a duration of 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insomnia | Insomnia will be measured with the Insomnia Severity Scale (0 to 28; higher scores correspond to worse severity) | Within one week of post-treatment | 
| Daytime sleepiness | Sleepiness will be measured with the Epworth Sleepiness Scale (0 to 24; a score of 10 or greater indicates excessive daytime sleepiness) | Within one week of post-treatment |