Variable | A | B | p Values | C | D | p Values |
---|---|---|---|---|---|---|
%hypo ≤2.5 (n=77) | %hypo >2.5 (n=21) | RDW ≤13.9% (n=42) | RDW >13.9% (n=35) | |||
Mean (SD) | Mean (SD) | A versus B | Mean (SD) | Mean (SD) | C versus D | |
Hb (g/dl) | 11.7 (0.6) | 10.7 (0.7) | <0.001 | 11.8 (0.7) | 11.5 (0.4) | 0.046 |
RBC (×1012/l) | 4.52 (0.28) | 4.51 (0.32) | NS | 4.51 (0.30) | 4.54 (0.27) | NS |
Hct (l/l) | 34.7 (1.9) | 33.1 (1.9) | 0.002 | 35.0 (2.0) | 34.3 (1.6) | NS |
MCV (fl) | 76.8 (3.0) | 73.5 (3.9) | 0.001 | 77.8 (3.0) | 75.6 (2.6) | 0.002 |
MCH (pg) | 25.9 (1.2) | 23.9 (1.5) | <0.001 | 26.2 (1.2) | 25.4 (0.9) | 0.002 |
MCHC (g/dl) | 33.7 (0.7) | 32.5 (0.8) | <0.001 | 33.8 (0.7) | 33.7 (0.7) | NS |
RDW (%) | 13.8 (1.0) | 15.4 (1.2) | <0.001 | 12.9 (0.6) | 14.5 (0.5) | NT |
ZPP (μmol/mol haem) | 48 (13) | 77 (29) | <0.001 | 44 (9) | 55 (15) | <0.001 |
Columns A and B indicate results of a comparison between 77 infants with %hypo ≤2.5 and 21 with %hypo >2.5. Columns C and D indicate results of a further comparison among the 77 infants with %hypo ≤2.5 using an RDW cut-off value of 13.9%. RDW was the variable used to differentiate group C from group D.
%hypo, percentage of hypochromic red cells; Hb, haemoglobin; Hct, haematocrit; MCV, mean cell volume; MCH, mean cell haemoglobin; MCHC, mean cell haemoglobin concentration; NS, not significant; NT, not tested; RBC, red blood cell count; RDW, red cell distribution width; ZPP, zinc protoporphyrin.