Trial Outcomes & Findings for The Feasibility of Home-Based Measurement of Circadian Timing for Veterans With TBI and Insomnia (NCT NCT05665764)

Veterans receiving outpatient care from a VA Medical Center were recruited between 7/2022 and 7/2024. No enrolled Veterans had a caregiver. Therefore, no caregivers were enrolled.

The Feasibility of Home-Based Measurement of Circadian Timing for Veterans With TBI and Insomnia

This outcome will be considered feasible if 70% participants provide adequate data for measurement of dim light melatonin onset (DLMO). DLMO will be estimated via the observed salivary melatonin levels using a variable threshold method, defined as the time of day when melatonin rises above the mean of the individual's first three saliva samples plus two standard deviations of those first three samples. Additionally, adequate data will entail: 1) collection and return of at least 5 saliva samples; 2) \<5 minutes discrepancy between the reported and pre-specified collection times for the two saliva samples ultimately used to estimate DLMO; and 3) 50 lux of light exposure within 30 minutes of the two saliva samples ultimately used to establish DLMO. Each individual who meets these criteria will be considered a successful estimation of salivary-based DLMO.

Dim light melatonin onset (DLMO) will be estimated using observed light exposure and sleep data via the extended Kronauer limit-cycle model of the human circadian pacemaker. This outcome will be considered feasible if 70% participants provide adequate actigraphy data. Adequate data will entail wearing the actigraphy device for at least 2 continuous days, with no interval of missing data (e.g., from covering the light sensor) during that time greater than 2 consecutive hours. Each Veteran who meets these criteria will be considered a successful estimation of actigraphy-based DLMO.

WHO Disability Assessment Schedule 2.0 (WHODAS 2.0). The WHODAS 2.0 is a reliable and valid assessment for health and disability that spans six domains of functioning, including cognition, mobility, self-care, interactions with others, life activities, and participation in community activities. The scale ranges between 1-5, with higher scores reflecting greater functional impairment. The outcomes of interest are the associations of the WHODAS 2.0 summary score with circadian-sleep misalignment (i.e., phase angles between reported attempted sleep onset and salivary DLMO or pDLMO). The outcome was a linear regression coefficient, which reflects the expected change in the total score of the measure per one-hour increase in a phase angle, adjusted for covariates. The phase angle was estimated after 1 week for salivary-based DLMO and as the average of daily values over the week for pDLMO.

Patient-Reported Outcomes Measurement Information System (PROMIS) sleep disturbance, a 27-item self-report measure of sleep quality and sleep disturbance. The range of the total score is 28.9-76.5, with higher values reflecting greater sleep disturbance. The outcomes of interest are the associations of the PROMIS total score with circadian-sleep misalignment (i.e., phase angles between reported attempted sleep onset and salivary DLMO or pDLMO). The outcome was a linear regression coefficient, which reflects the expected change in the total score of the measure per one-hour increase in a phase angle, adjusted for covariates. The phase angle was estimated after 1 week for salivary-based DLMO and as the average of daily values over the week for pDLMO.

The difference in timing between dim light melatonin onset measured by self-collected saliva and the average sleep diary-based bedtime.

The difference in timing between dim light melatonin onset measured by actigraphy and the average sleep diary-based bedtime.