The Feasibility of Home-Based Estimation of Circadian Timing in Veterans With Insomnia and Past Traumatic Brain Injury

OBJECTIVE: To evaluate the feasibility and acceptability (eg, user experience) of 2 methods for home-based estimation of circadian timing among veterans with insomnia and a history of traumatic brain injury (TBI). SETTING: An outpatient setting at a Department of Veterans Affairs medical center. PARTICIPANTS: Veterans between the ages of 18 and 64 years with current insomnia and a history of mild-to-severe TBI. DESIGN: A prospective observational study evaluating the feasibility of 2 home-based methods for estimating circadian timing, that is, dim light melatonin onset (DLMO): (1) indirect prediction of DLMO using activity and light-exposure data collected through actigraphy (ie, pDLMO); and (2) estimation of DLMO via direct measurement of melatonin in self-collected salivary samples (ie, salivary DLMO). Participants wore an actigraphy device and completed sleep diaries for one week. They then spent one evening self-collecting 7 saliva samples under dim light conditions. Finally, participants completed a brief qualitative interview on their experiences. MAIN MEASURES: Primary outcomes were the success rates for estimation of each home-based DLMO method. Feasibility was set as 70% successful estimation for a given measure, for those who completed the respective procedures. RESULTS: pDLMO could be estimated for 27 of 29 participants (93.1%) who completed actigraphy data collection, meeting the feasibility goal. Salivary DLMO could only be estimated for 7 of 28 participants (25%) who completed saliva collection. Participants broadly expressed acceptance of both home-based DLMO methods and a willingness to use them again. Several barriers related to each method were identified that can inform future implementation efforts with this patient population. CONCLUSION: pDLMO is feasible and acceptable for estimating circadian timing in veterans with insomnia and past TBI. Using pDLMO could help identify circadian-sleep misalignment after TBI, helping personalize insomnia treatments based on patient-specific needs and interrupting the bidirectional cycle of insomnia and circadian dysregulation.