The value of the peripheral blood smear in anemic inpatients. The laboratory's reading v a physician's reading.

Since physicians are routinely taught to review the peripheral blood smear results of all anemic patients, we analyzed the diagnostic value of the laboratory's blood smear reading and the incremental value of a physician's personal reading in anemic inpatients. Blood smear abnormalities, as reported by the laboratory and two hematologists, were poorly reproducible, with only five of the 11 types of abnormalities being more reproducible than could be expected by chance. The blood smear performed no better than RBC indices in detecting probable iron deficiency or low serum levels of folate or vitamin B12. In anemias not caused by deficiency states, the blood smear reading performed by the hospital laboratory provided unique information in 6% of the cases and helpful information in another 25%, but the additional reading performed by a hematologist never provided unique information and provided incremental helpful information in only 4% of the cases. The peripheral blood smears of all anemic inpatients should be read by the hospital laboratory, but in our hospital, a routine additional personal reading by a physician had limited incremental value and could be reserved for selected cases.