Abstract
BACKGROUND: Anemia is a prevalent condition in the elderly (aged ≥65 years), associated with increased morbidity, mortality, and reduced quality of life. Despite its impact, comprehensive data on its prevalence, etiology, and outcomes in this population are limited. OBJECTIVE: To synthesize evidence on the prevalence, etiology, and clinical outcomes of anemia in individuals aged 65 years and older, informing clinical practice and future research. METHODS: A systematic search was conducted across PubMed, Scopus, Web of Science, and Google Scholar (2004-2024), identifying 47 studies (observational, cohort, cross-sectional, and review). Inclusion criteria focused on anemia in the elderly, reporting prevalence, etiology, or outcomes. Quality was assessed using the Newcastle-Ottawa Scale and AMSTAR 2. Narrative synthesis, supported by biostatistical analyses (pooled prevalence, hazard ratios [HRs], odds ratios, 95% confidence intervals [CIs]), was performed, with heterogeneity assessed via I² statistics. RESULTS: Anemia prevalence ranged from 10% to 50% (pooled prevalence 27.8%, 95% CI: 22.1-33.5, I² =92%), higher in hospitalized patients (37.4%, 95% CI: 29.8-45.0) than community-dwelling elderly (23.1%, 95% CI: 18.2-28.0). Iron deficiency anemia (27.5%, 95% CI: 21.3-33.7), anemia of chronic disease (20.1%, 95% CI: 15.6-24.6), and unexplained anemia (34.2%, 95% CI: 28.0-40.4) were predominant. Anemia increased all-cause mortality (pooled HR: 2.85, 95% CI: 2.10-3.87, I² =78%) and cardiovascular events (pooled HR: 3.12, 95% CI: 2.34-4.16, I² =65%). CONCLUSION: Anemia in the elderly, particularly unexplained anemia, is a significant health burden, necessitating targeted diagnostic and therapeutic strategies.