Evaluating Anemia in Older Adults

Anemia in older adults is a common finding and frequently results in a request for hematology consultation.

To define anemia, we follow the hemoglobin criteria defined by Beutler and Waalen in Table 73-1. However, hemoglobin trajectory over time is as important. Based on the fact that the average hemoglobin level declines in older adults about 1 g/dL over 15 years or more, we consider decline of 1 g/dL in less than 5 years or 2 g/dL over 10 years significant and supports a complete evaluation. We work diligently to retrieve remote blood counts. Older adults frequently have had blood counts obtained either routinely in the past, before a procedure, or at the time of hospital admission. Counts at the time of hospital admission may be the least reliable because they occur in the context of an illness.

To elicit symptoms, both the patient and family members or caregivers who know the patient are asked about functional changes (walking, naps, activity level) over the short-term (weeks) and longer term (months to years). Many older adults will often attribute functional changes to “old age.”

Our basic evaluation begins with a complete blood count, red cell indices, and review of the peripheral smear. The red cell size by mean corpuscular volume is helpful but imperfect. We also perform a reticulocyte count, but 95% or more of anemias in older adults are hypoproliferative. Because anemia can be mixed or multifactorial, we routinely perform the same panel on most patients: serum ferritin, serum iron, total iron-binding capacity, serum creatinine (and estimated renal function), vitamin B₁₂