Which finding suggests a stable form of anemia in a patient?

A normal red blood cell distribution width (RDW) is indicative of a stable form of anemia because it suggests that the size of red blood cells is consistent. In a stable anemia situation, the red blood cells typically maintain a uniform size, which points to a chronic or long-standing process rather than an acute or severe state. High variability in RDW would suggest a more complex process, such as recent blood loss or nutritional deficiencies, which are usually associated with instability.

In contrast, increased ferritin levels would generally indicate adequate iron stores, which may not be consistent with anemia. High mean corpuscular volume (MCV) suggests macrocytic anemia, often associated with conditions like vitamin B12 deficiency or folate deficiency, which are not stable forms of anemia. Lastly, low hemoglobin levels alone do not provide a comprehensive understanding of the stability of anemia, since it is crucial to assess other factors such as RDW and the presence of symptoms to determine the stability of the anemia.