Social Determinants of Emergency Department Utilization, Overuse, and Access Barriers Among Adults: A Systematic Review.

Emergency departments (EDs) are facing increasing adult demand, and socially driven patterns of repeated, avoidable, or nonurgent use remain insufficiently synthesized across healthcare settings. ED utilization is influenced not only by clinical need but also by broader social and structural conditions that shape access to healthcare. This systematic review examined the social determinants associated with ED utilization, overuse, repeated attendance, and access barriers among adults. A structured search of major biomedical and health services databases was conducted, and eligible studies were reviewed using predefined inclusion and exclusion criteria. Because of variation across study designs, populations, and outcome definitions, findings were synthesized narratively. The review found that ED use was consistently associated with socioeconomic disadvantage, unmet social needs, poor access to timely primary care, weak social support, neighborhood deprivation, and broader health system barriers. Common drivers included low income, food insecurity, public insurance dependence, unstable housing, limited continuity of care, transportation difficulties, and restricted availability of alternative services. Across settings, repeated or nonurgent ED use often appeared to reflect unmet need and constrained access rather than simple inappropriate use. These findings suggest that socially driven ED utilization should be understood as a health equity issue requiring more responsive primary care, stronger social support pathways, and better integration between emergency services and community-based care.