Digital Exclusion and Sleep Problems in Middle-Aged and Older Adults: A Multi-Cohort Cross-National Study

Digital exclusion has been recognised as a social determinant of health, but its prospective relationship with sleep in international ageing cohorts is unknown. We analysed harmonised individual-level data from the Health and Retirement Study (HRS; USA, n = 13,876), the China Health and Retirement Longitudinal Study (CHARLS; n = 12,131) and the Survey of Health, Ageing and Retirement in Europe (SHARE; n = 65,530). Digital exclusion and sleep were measured using cohort-specific indicators: email/internet non-use (HRS), online social-networking non-use (CHARLS) and internet/email non-use (SHARE); sleep outcomes were symptom-based (HRS), duration/restlessness-based (CHARLS) and medication-based (SHARE). Progressive logistic regression, lagged longitudinal models (wave T exposure, wave T + 1 outcome), and temporally ordered mediation (depressive-symptom pathway) were applied. In lagged longitudinal analyses, digital exclusion was associated with subsequent sleep problems in CHARLS (OR 1.47, 95% CI 1.18-1.83) and SHARE (OR 1.79, 95% CI 1.53-2.09); the HRS association was non-significant (OR 1.08, 95% CI 0.98-1.19). Between-cohort heterogeneity was very high (I²=93.6%). Depressive symptoms explained approximately 47% of the association in SHARE. Crude SHARE transition analyses showed a graded pattern by exclusion persistence, but the adjusted stable-excluded estimate was non-significant. Digital exclusion was prospectively associated with sleep problems in CHARLS and SHARE, but not significantly in HRS. Findings should be interpreted in light of non-equivalent exposure and outcome definitions. Depressive symptoms represented an important pathway. Digital inclusion warrants further investigation as a potential target for sleep-health intervention research.