Research Trends in Frailty and Delirium in Older Adults: A Bibliometric Analysis.

Background/Objectives: Frailty and delirium represent critical geriatric syndromes with profound implications for older adults' health outcomes. This study aimed to quantitatively map global research trends and thematic developments in frailty and delirium among older adults through a bibliometric approach. Methods: A literature search was conducted in the Web of Science Core Collection up to 11 May 2026. Bibliometric analyses were performed using VOSviewer, CiteSpace, and the R package "bibliometrix". Results: The analysis included 911 publications published between January 2006 and May 2026, involving 6805 authors from 337 journals. The USA dominated research output with 185 articles (20.3%) and the highest total citations (8507). Harvard University led institutional contributions (139 articles), while Age and Ageing emerged as the most influential journal (h-index = 21). Bellelli Giuseppe was the most productive and impactful author. Keyword co-occurrence analysis identified six thematic clusters: adverse outcomes and comprehensive geriatric assessment, cognitive decline and neuropsychiatric disorders, perioperative and intensive care settings, postoperative delirium and geriatric complications, prediction and validation tools, and epidemiology and management-related themes. Temporal keyword bursts revealed recent emphases on "anesthesia" (2022-2026) and "cardiac surgery" (2023-2024). Conclusions: This bibliometric analysis demonstrated a sustained increase and diversification in research on frailty and delirium in older adults over the past two decades. The field has evolved from foundational clinical and epidemiological studies to multidisciplinary, outcome-oriented research, with growing attention to perioperative care and comprehensive assessment.