Am. Kis et M. Carnes, DETECTING IRON DEFICIENCY IN ANEMIC PATIENTS WITH CONCOMITANT MEDICALPROBLEMS, Journal of general internal medicine, 13(7), 1998, pp. 455-461
OBJECTIVE: To determine the sensitivity and specificity of mean corpus
cular volume, transferrin saturation, total iron-binding capacity, and
ferritin level in determining iron deficiency in a population of anem
ic veterans with a wide variety of general medical diagnoses. DESIGN:
Retrospective chart review. SETTING: Hospitals of the Department of Ve
terans Affairs in Madison and Milwaukee, Wisconsin. PARTICIPANTS: One
hundred one anemic veterans with any medical condition who underwent b
one marrow aspiration and serum iron studies. MEASUREMENTS AND MAIN RE
SULTS: Using the presence or absence of bone marrow hemosiderin as the
reference standard, the sensitivity and specificity of the following
serum iron indicators were calculated: mean corpuscular volume, transf
errin saturation, total iron-binding capacity, and ferritin level. Of
these patients, 41 (40.6%) were categorized as iron deficient, with no
stainable bone marrow hemosiderin. A serum ferritin level less than o
r equal to 100 mu g/L provided the best sensitivity (64.9%) and specif
icity (96.1%) for evaluating iron stores in this patient population. W
hen performed within 24 hours of bone marrow examination, a serum ferr
itin level less than or equal to 100 mu g/L was 100% accurate in separ
ating iron-deficient from iron-sufficient patients. None of the other
serum iron indicators alone or in combination performed better than fe
rritin level alone. CONCLUSIONS: In a population of anemic veterans wi
th a wide variety of concomitant medical problems, a serum ferritin le
vel less than or equal to 100 mu g/L was optimal for determining iron
deficiency. This is higher than the ferritin level of less than or equ
al to 50 mu g/L cited in standard textbooks as evidence of iron defici
ency in patients with inflammation, infection, or malignancy.