Everyone realizes the pitfalls and difficulties that all except the most highly trained hematologists encounter in the differentiation of the anemias. Mistakes in diagnosis are not uncommon; especially is this true when the busy clinician mistakes a severe secondary anemia, such as may occur in connection with carcinoma, for a case of pernicious anemia.1 In just such types of cases anything that may aid in making a correct diagnosis simply and rapidly is worthy of consideration. Our aim, therefore, was to determine what clinical value, if any, the icterus index might have in this direction.
We have interested ourselves primarily with a clinical fact, namely, the intensity of the yellow color of the blood serum, and in this study have not concerned ourselves particularly with the numerous considerations as to the possible sources of this color.
As this was to be a clinical test, the simplest and most rapid means