Effects of Chronobiology-guided Lifestyle Interventions on Insomnia Severity, Cognitive Performance, and Sleepiness

Study Overview
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Brief Summary
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Poor sleep is closely related to circadian misalignment; shift workers often experience shift work disorder characterized by excessive sleepiness and recurrent shift work schedules-associated insomnia. This study aims to examine the effects of a program of chronobiology-guided lifestyle interventions (CGLI) on insomnia severity, cognitive performance (psychomotor vigilance and processing speed), and sleepiness in female nurses undertaking rotating-shift work.

Detailed Description
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This study will use a parallel-group, randomized, assessor-blind, wait-list controlled design to determine the effects of a program of multimodal lifestyle interventions based on chronobiology, consisting of timed bright light exposure, meal timing manipulations, and sleep hygiene education on insomnia severity, cognitive performance (psychomotor vigilance and processing speed), and sleepiness in female nurses undertaking rotating-shift work.

Official Title
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Effects of Chronobiology-guided Lifestyle Interventions on Insomnia Severity, Cognitive Performance, and Sleepiness in Female Rotating-shift Nurses: a Randomized Controlled Trial

Conditions
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Circadian Rhythm Sleep Disorder

Intervention / Treatment
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* Behavioral: Chronobiology-guided lifestyle interventions


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Females aged 20 to 60 who work full time as a nurse and work a 3-shift rotation, including day shifts, evening shifts, and night shifts in the most recent 6 months. Participants must complain of insomnia symptoms and/or sleepiness in relation to shift work schedule for at least 3 months. Participants must have10 workdays (evening or night shift) within a 14-day period during the study period. Exclusion Criteria: Active physical diseases. Moderate to severe psychopathology. Medications or treatments that may affect sleep. Pregnant or breastfeeding. Participants must be free of ophthalmic pathology, eye surgery, and diseases affecting the retina or taking photosensitizing drugs. Participants who have been diagnosed with sleep-disordered breathing will be excluded. Sleep-disordered breathing such as obstructive sleep apnea (OSA) will be screened using the snoring, tiredness, observed apnea, high BP, BMI, age, neck circumference, and male gender (STOP-BANG) questionnaire.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Chronobiology-guided lifestyle interventions group<br>A multimodal program that includes (1) timed bright light therapy, (2)guidance on meal timing, and (3) sleep hygiene education. | Behavioral: Chronobiology-guided lifestyle interventions<br>* 1) timed bright light exposure using blue-enriched white light glasses, 2) recommendations for meal timing, and 3) sleep hygiene education<br>|
| No Intervention: wait-list control group<br>The participants in the wait-list group will be told that they are on a waiting list during the first 2 weeks to serve as the no-treatment control. Chronobiology-guided lifestyle interventions will be conducted after the posttest is completed. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| insomnia severity | The Insomnia Severity Index will be used to determine the severity of insomnia. The Insomnia Severity Index with a total score ranging from 0 to 28. A higher Insomnia Severity Index score indicates more severe insomnia. | Through study completion, an average of 14days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The neurobehavioral function of cognitive performance | The neurobehavioral function will be evaluated using the Walter Reed Psychomotor Vigilance Test (PVT), a portable reaction-time test based on the Dinges and Powell digital test. The PVT will be testing a 5-min test with responses to randomly spaced stimuli per test. | Through study completion, an average of 14 days | 
| The processing speed of cognitive performance | A Tablet-based Symbol Digit Modalities Test (T-SDMT) will be used to test processing speed. | Through study completion, an average of 14 days | 
| The sleepiness at work | The Karolinska Sleepiness Scale (KSS) will be used to measure sleepiness at work. It is on a scale of 1 to 9. A higher score is more sleepy. | Through study completion, an average of 14 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chonobiology, Cognitive performance, Insomnia, Shift work, Sleepiness