Role of Sleep Reactivity in Shift Work Disorder (REACT)

Henry Ford Health

Status: Enrolling

Conditions: Shift-work Disorder

Treatments: Behavioral: Sleep education control; Behavioral: Active phototherapy; Behavioral: Cognitive Behavioral Therapy (CBT); Behavioral: Control phototherapy

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT05424406

R01HL160870 (Other Grant/Funding Number)

15661

Details and patient eligibility

About

The purpose of this project is to test sleep reactivity as an independent cause of Shift Work Disorder (SWD). The primary hypothesis is that those with high sleep reactivity will show persistent SWD symptoms after experimental reduction of circadian misalignment, which will then be mitigated with CBT.

Full description

The first aim of this study is to establish sleep reactivity as a predictor of insomnia in SWD independent from circadian misalignment. The second aim of this study is to establish sleep reactivity as a predictor of sleepiness in SWD independent from circadian misalignment. The third aim of this study is to probe sleep reactivity as a cause of insomnia in SWD. The fourth aim of this study is to probe sleep reactivity as a cause of sleepiness in SWD.

Participants with Shift Work Disorder (SWD, N=150) with high and low sleep reactivity will be enrolled. This study will use a two-step mechanistic randomized controlled trial design stratified by high and low sleep reactivity to examine the independent effect of sleep reactivity in SWD after experimental reduction of circadian misalignment. The first step will experimentally reduce circadian misalignment compared to a control. Those who achieve reduced circadian misalignment (melatonin onset at or later than 4am, i.e., compromised phase position) and remain symptomatic will continue to the second step where sleep reactivity will be probed with CBT compared to a sleep education control.

Enrollment: 150 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Participants must be working a fixed nightshift schedule, operationalized as: a) working at least three night shifts a week, b) shifts must begin between 18:00 and 02:00, and last between 8 to 12 hours, and c) must also plan to maintain the nightshift schedule for the duration of the study
• Participants must have Shift Work Disorder, which will be diagnosed based on ICSD-3 criteria
• Participants must show circadian misalignment, operationalized as a baseline melatonin onset between 18:00 and 01:00.
• Participants must be at least 18 years old

Exclusion criteria

• Insomnia disorder or excessive sleepiness predating the onset of shift work
• Termination of nightshift schedule
• Presence of other sleep disorders (e.g. obstructive sleep apnea, narcolepsy) determined by standard clinical polysomnography
• Diagnosis of bipolar disorder
• History of neurological disorders determined by self-report and medical history
• Pregnancy
• Alcohol use disorder
• Illicit drug use via self-report and urine drug screen if reasonable suspicion to test

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Sequential Assignment

Masking: Double Blind

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150 participants in 4 patient groups

Active light condition

Experimental group

Description:

Timed bright light exposure will be delivered in a controlled laboratory setting (10,000 lux) designed to delay the DLMO to 4 am or later. This would shift the circadian nadir (e.g., the period of maximal sleepiness) into the typical daytime sleep period after the nightshift (i.e., circadian nadir at \~10am). Bright light will be delivered in a controlled lab environment using a full spectrum light-box with UV filter (Sunbox Sunray II) to achieve a robust reduction of circadian misalignment. The light schedule will be tailored to each individual nightshift worker, determined by: 1) their baseline circadian phase, and 2) the human phase response curve adjusted to the individual's baseline circadian phase.

Treatment:

Behavioral: Active phototherapy

Control light condition

Active Comparator group

Description:

Shift workers randomized to the control condition will receive less intense light that still has a perceptible alerting effect (100 photopic lux). However, light will occur during a portion of the phase response curve with minimal phase shifts.

Treatment:

Behavioral: Control phototherapy

Cognitive Behavioral Therapy (CBT) condition

Experimental group

Description:

The CBT condition will probe sleep reactivity using validated CBT strategies over 6 sessions in accordance with the two-factor theory of emotion. Behavioral strategies will be used to reduce physiological arousal (e.g., relaxation training, breathing) and to strengthen behavioral cues for sleep (e.g., sleep hygiene and sleep scheduling). Sleep times will be scheduled to align with the reduced circadian misalignment (compromised phase position, i.e., maintaining a slightly delayed sleep period on offwork days). Cognitive strategies will identify stressors (e.g., dysfunctional beliefs about sleep) and intervene on worry and rumination with cognitive reappraisal and active coping. Sessions will be conducted by a trained behavioral sleep medicine provider via telemedicine to increase accessibility.

Treatment:

Behavioral: Cognitive Behavioral Therapy (CBT)

Sleep education control condition

Active Comparator group

Description:

This condition will use an established sleep education control protocol modified for nightshift workers based on the "Plain Language about Shiftwork" published by the National Institute for Occupational Safety and Health (NIOSH). Sleep duration recommendations will be equivalent to the CBT group (8 hours of sleep opportunity) to ensure that outcomes are not confounded by time in bed. Materials in the sleep education control condition will be separated into weekly electronic materials monitored for engagement and completion.

Treatment:

Behavioral: Sleep education control