Mapping Temporal Dynamics in Hospice Research: A Topic Modeling Analysis of PubMed Abstracts

BACKGROUND: Hospice care has expanded significantly in recent decades; however, few studies have systematically examined how research themes in this field have evolved over time. OBJECTIVES: This study aimed to explore the temporal dynamics of hospice care research using topic modeling, identifying emerging and declining areas of focus. METHODS: A total of 14,862 hospice-related articles published up to April 2025 were retrieved from PubMed. Topic modeling analysis was conducted using Latent Dirichlet Allocation to extract thematic structures across the corpus. The optimal number of topics was determined using perplexity, the elbow method, and coherence scores. Temporal trends were assessed across four stages defined by major World Health Organization milestones: the (1) Foundation (≤2001), (2) Expansion (2002-2013), (3) Institutionalization (2014-2019), and (4) Post-pandemic Transition (2020-2025) periods. RESULTS: Ten major research topics were identified, including caregiver support, advance care planning, access to hospice care, and mortality trends. Topic prevalence shifted over time, with increased attention to caregiver support and advance care planning during the Expansion and Institutionalization periods and heightened focus on access to care and mortality trends during the Post-pandemic Transition period. CONCLUSION: Hospice research has shifted from foundational and conceptual inquiries to more applied and policy-oriented themes. The findings reflect the field's growing institutionalization and underscore the need for sustained research targeting underserved areas to promote equity and responsiveness in end-of-life care.