Care Recipient Functional Limitations, Caregiver Burden, and Sleep Disturbance: A Half-Longitudinal Mediation Analysis Using Nhats and Nsoc

Background and Purpose

Family caregivers of older adults with functional limitations often experience disrupted sleep, a critical yet understudied outcome that can affect their health, caregiving quality, and the likelihood of institutionalization for care recipients. Guided by the Stress Process Model (1990) and the Theory of Dyadic Illness Management (2018), this study hypothesized that objective care demands serve as a primary stressor that influences caregiver sleep partly through subjective caregiver burden. Although the theoretical pathway is well-established, few population-based longitudinal studies have tested it using nationally representative data. The present research examined whether caregiver burden mediates the relationship between care recipient functional limitations and caregiver sleep disturbance one year later.

Methods

Data were drawn from three linked surveys: the National Health and Aging Trends Study (NHATS) Round 13 Sample Person and Other Person Files (2023), and the National Study of Caregiving (NSOC) Round 13 (2023, Time 1) and Round 14B (2024, Time 2). The analytic sample comprised 2,125 family caregivers of community-dwelling older adults, representing approximately 19.5 million caregivers nationwide. Functional limitations of care recipients at T1 were measured by the number of daily (five ADL) and instrumental (four IADL) activities requiring assistance. Caregiver burden at T1 was assessed with a four-item scale reflecting feelings of exhaustion, being overwhelmed, lack of time for oneself, and disrupted routines (α = 0.82). Sleep disturbance was measured at both time points using two items related to trouble falling back asleep and disrupted sleep, with higher scores indicating greater disturbance. A half-longitudinal mediation model was estimated using survey-weighted regression and NSOC Round 14B weights. Baseline sleep and covariates such as demographic characteristics, health status, and caregiving duration were controlled. Indirect effects were tested using Sobel-type and nonparametric bootstrap methods with 1,000 replications that preserved survey design.

Results

Care recipient functional limitations at T1 significantly predicted caregiver sleep disturbance at T2. This effect operated partly through caregiver burden: greater limitations were linked to higher burden, which in turn was associated with poorer sleep. The direct effect remained significant after accounting for burden, indicating partial mediation that explained roughly ten percent of the total effect. Bootstrap tests confirmed the indirect pathway. Sensitivity analyses showed stronger mediation for instrumental than basic activity limitations, and stratified models revealed this effect only among female caregivers, pointing to gendered psychological mechanisms.

Conclusions and Implications

Using nationally representative longitudinal data, this study provides evidence that caregiver burden partly mediates the association between care recipient functional limitations, particularly instrumental needs, and subsequent caregiver sleep disturbance. Results support the Stress Process framework and the Theory of Dyadic Illness Management, underscoring modifiable targets for intervention. Social work practice should include regular screening for caregiver burden and sleep problems, expanding access to burden-reduction strategies such as psychoeducation, respite services, and peer support. Gender-tailored approaches are also warranted, given women’s heightened sensitivity to the burden–sleep pathway. Because caregiver sleep disturbance contributes to care recipient institutionalization and long-term care expenditures, addressing this mediational process has meaningful implications for public health and aging policy.