Insomnia Symptom Trajectory of Spouse Caregivers of Older Adults with Functional Limitations.

Objectives: This study examined the long-term impact of spouse caregiving on insomnia symptoms, compared to propensity-score matched non-caregivers.

Methods: Health and Retirement Study data between 2006 and 2018 were used. Caregivers (n = 403) were respondents (aged 50+) who assisted their heterosexual spouses in performing (instrumental) activities of daily living at baseline. Non-caregivers were matched using a propensity score matching procedure based on baseline characteristics. Insomnia symptoms were measured every 4 years for both groups. Poisson mixed-effect models estimated the association between caregiver status and insomnia symptoms.

Results: Compared to matched non-caregivers, caregivers had similar severity of insomnia symptoms at baseline (${\beta }_{\mathrm{caregiver}}$ = 0.018, 95% CI = -0.089, 0.124) and reported a similar yearly change rate (${\beta }_{\mathrm{caregiver}\times \mathrm{time}}$ = -0.008, 95% CI = -0.017, 0.001). No moderation effects of care-recipients' dementia status and social support were significant.

Conclusions: In this study sample, there is no evidence that spouse caregivers, specifically those who performed light duties, experience more severe insomnia symptoms than non-caregivers.

Clinical implications: Spouse caregiving, especially in a light-duty capacity, may not be detrimental to the caregivers' sleep health. More data are needed regarding insomnia in spouse caregivers with heavy duties of care to fully assess the health impact of the caregiving experience.