Prevalence and outcomes of anemia in geriatrics: a systematic review of the literature.

Anemia is a common concern in geriatric health, but its exact incidence and prevalence are unclear. Several studies have addressed this issue with discrepant results. Estimates of anemia prevalence reported in the articles reviewed here range from 2.9% to 61% in elderly men and from 3.3% to 41% in elderly women. This variability is related to a number of factors, including the setting of the study, the health status of the subject population, and the criteria used to define anemia. The criteria set by the World Health Organization (WHO)--hemoglobin level <120.0 g/L for women and <130.0 g/L for men--are most frequently, but not universally, used. Even so, their appropriateness in older populations may be questioned. Most existing reports indicate that elderly men have higher rates of anemia than do elderly women, but the threshold values are, in general, higher for men than for women. Incidence of anemia rises with age; some studies report a particularly notable increase in prevalence of anemia in the oldest subjects, those > or =85 years of age. Whereas anemia is associated with symptoms ranging from weakness and fatigue to increased falls and depression, and in severe cases can lead to congestive heart failure, few studies have systematically examined functional, clinical, and economic outcomes or patient satisfaction in the elderly with anemia. Future directions for research on anemia should include a more detailed examination of the importance of aging or age-related diseases on the pathogenesis of anemia, an assessment of the importance of anemia on outcomes such as physical function and cognitive function, and an analysis of whether impairments associated with anemia are amenable to correction by improving hemoglobin concentration.