Table 2.

Domains and constructs covered in baseline veteran and caregiver surveys, and items used to assess each domain.

Domain and construct			Measure or item source
Both veteran and caregiver survey
	Relationship between veteran and caregiver	Behavioral Risk Factor Surveillance System caregiver module [43] Dyadic Relationship Scale [57] Family Resilience Scale for Veterans [58]
	Length of care	Modified Behavioral Risk Factor Surveillance System. caregiver module [43]
	Caregiving tasks	Modified NACa Questionnaire [44]
	Amount of care	NAC Questionnaire [44]
	Primary caregiver	Modified NAC Questionnaire [44]
	Social support	Perceived social support from the Veterans Health Study [59]
	Health status	The Veterans RAND-12 item Health Survey [51]
	Sleep	Insomnia Severity Index [60]
	Traumatic brain injury screener	Ohio State University Traumatic Brain Injury Identification Method [40,61]
	Service use	Modified O’Malley Measure of Caregiver Service Use [56]
	Stress	Perceived Stress Scale-14 [62]
	Thriving	Brief Inventory of Thriving [63]
	Loneliness	Three-Item Loneliness Scale [64]
	COVID-19	Lived Experience of Epilepsy: Patient and Caregiver Perspectives Study [65] Beach Questionnaire [66]
	Anxiety	Generalized Anxiety Disorder 2-item [67]
	Depression	Patient Health Questionnaire-2 [68]
Veteran survey only
	Posttraumatic epilepsy screen	US National Institute of Neurological Disorders and Stroke common data element
	Illness perception	Brief Illness Perception Questionnaire [69]
Caregiver survey only
	Distance from Veteran	NAC Questionnaire [44]
	Challenging behaviors	Care recipient impairment: problem behaviors subscale [70]
	Positive aspects of caregiving	Caregiving Uplifts Scale [71]
	Resilience	Response to Stressful Experiences Scale-4 [72]
	Caregiver choice	NAC Questionnaire
	Incident health conditions since starting caregiver	Delgado Survey [73]
	Payment and financial support	Delgado Survey [73]
	Loss of self	Loss of Self Scale [74]
	Caregiver burden	Zarit Burden Interview-12 [50]

^aNAC: National Alliance for Caregiving.