A patient's red cell indices can be used in discriminant functions to aid in the diagnosis of microcytic anemia.
Red cell indices used:
(1) MCH in picograms
(2) MCV in femtoliters
(3) RBC count as 10^12/L
(4) RDW in percent
Coefficient |
Normal |
Alpha- |
Beta- |
Iron-deficiency anemia |
MCH |
6.388 |
4.613 |
4.852 |
3.249 |
MCV |
3.981 |
3.616 |
3.277 |
4.115 |
RBC |
24.101 |
24.314 |
23.865 |
20.607 |
RDW |
9.936 |
10.164 |
10.011 |
10.842 |
constant |
-396.710 |
-325.996 |
-303.446 |
-325.140 |
group classification function =
= ((coefficient for MCH) * (MCH in picograms)) + ((coefficient for MCV) * (MCV in femtoliters)) + ((coefficient for RBC) * (RBC in 10^12/L)) + ((coefficient for RDW) * (RDW in percent)) + (constant)
Interpretation:
• The group with the highest classification function result is the probable diagnosis.
NOTE: When the data on page 681 is entered into the equations, my results are about 55-57 points lower than that given in the paper (260.72 vs 315.003, etc.)
Purpose: To use a patient's red blood cell indices to aid in the diagnosis of microcytic anemia.
Specialty: Hematology Oncology, Clinical Laboratory
Objective: laboratory tests, criteria for diagnosis, differential diagnosis and mimics, red flags
ICD-10: D50, D56,