Longitudinal associations between time-varying insomnia symptoms and all-cause health care services utilization among middle-aged and older adults in the United States.

OBJECTIVE: To examine longitudinal associations between time-varying insomnia symptoms (difficulty initiating sleep, difficulty maintaining sleep, early-morning awakenings, and nonrestorative sleep) and all-cause health care services utilization (HSU), including overnight hospital stays, nursing home stays, and home health care services among middle-aged and older adults.

DATA SOURCES: The Health and Retirement Study (HRS), a nationwide, population-representative survey of primarily middle-aged and older adults in the United States.

STUDY DESIGN: This study is an analysis of prospective data from the HRS for a cohort of 13,168 adults (aged ≥50 years; females = 57.7%). Study participants were followed for 16 years. This study focuses on the associations between time-varying insomnia symptoms, both cumulatively and independently, and repeated HSUs. A marginal structural modeling approach was used to capture time-varying biological, psycho-cognitive, and behavioral health factors, and to adjust for selection bias such as differential loss to follow-up. Generalized estimating equations were employed to compute average marginal effects and their 95% confidence intervals.

DATA COLLECTION/EXTRACTION METHODS: We extracted longitudinal data from 2002 through 2018 waves of the HRS.

PRINCIPAL FINDINGS: Experiencing higher numbers of insomnia symptoms on a cumulative scale was associated with higher probabilities of HSU. For instance, the likelihood of overnight hospital stays for individuals reporting one symptom increased from 4.7 percentage points on average (95% CI: 3.7-5.6, p < 0.001), to 13.9 percentage points (95% CI: 10.3-17.5, p < 0.001) for those reporting four symptoms, relative to individuals experiencing no insomnia symptoms. Further, experiencing each of difficulty initiating and maintaining sleep, and nonrestorative sleep, as standalone symptoms, was associated with a higher likelihood of HSU when compared to those not experiencing the symptoms.

CONCLUSIONS: The results demonstrate the potential consequences and adverse impacts of insomnia symptoms on HSU among middle-aged and older adults. Future investigations should focus on the underlying causes and health systems pathways linking insomnia symptoms to HSU.