Table 3.
Studies comparing Hb and hct levels in blood obtained from various anatomical sites
| S. No. | Authors | Parameter | Method | Mean value (±SD) of ELS | Mean value (±SD) of FS | Mean value (±SD) of VS | Inference |
|---|---|---|---|---|---|---|---|
| 1 | Avoy et al13 | hct (%) | Microhematocrit | 46.84±4.24 (male) 42.85±6.00 (female) |
44.14±3.20 (male) 40.34±2.68 (female) |
42.26±2.60 (male) 38.30±2.60 (female) |
Statistically significant difference in ELS, FS and VS (p<0.05) |
| 2 | Coburn et al15 | hct (%) | Microhematocrit | 47.820±3.978 | 40.640±3.141 | 40.860±2.680 | ELS hct significantly higher than FS and VS (p<0.05) |
| 3 | Pi et al16 | Hb (g/dL) | FS by Hemocue, VS by automated hematology analyzer | – | 13.5±1.02 | 13.26±0.72 | FS capillary sample has 0.32 g/dL higher Hb level |
| 4 | Wood et al14 | hct (%) | Microhematocrit | 47.3±4.2 | 42.7±2.8 | 42.5±3.1 | Hct determinations from ELS samples Overestimate venous Hct. FS more sensitive in detecting anemia |
| 5 | Radtke et al2 | Hb (g/dL) | ELS and FS by PH, VS by hematology analyzer | 15.96±1.57 (male) 13.7±1.41 (female) |
14.99±1.28 (male) 13.32±1.1 (female) |
14.59±1.15 (male) 12.97±1.07 (female) |
Mean overestimation with ear-stick sample was 7.8% 89% donors with unacceptable Hb level would pass the ear-stick Hb screening |
| 6 | Darragh et al17 | Hb (g/dL) | FS by Hemocue, VS by hematology analyzer | – | 13.1±0.2 (male) 12.1±0.2 (female) |
14.1±0.7 (male) 12.8±0.6 (female) |
A cutoff for capillary Hb of 12 g/dL for females and 13 g/dL for males equates to venous Hb that meets regulatory requirements:12.5 and 13.5 g/dL, respectively |
| 7 | Schalk et al18 | Hb (mmol/L) Hct (L/L) |
Hematology analyzer Advia 120 | – | 8.2±1.5 0.40±0.07 |
8.0±1.5 0.38±0.07 |
Mean differences between capillary and venous hematological values of +1.8% |
| 8 | Zeimann et al19 | Hb (g/dL) | FS by Hemocue, VS by hematology analyzer | – | 15.59±1.08 (male) 13.73±1.01 (female) |
15.38±0.87 (male) 13.64±0.91 (female) |
Mean deviation 0.54 g/dL Concordance between capillary and venous measurements in 93.3% of female donors and 98.7% of male donors |
| 9 | Rudolf-Oliveira et al20 | Hb (g/dL) | Hemocue HemoControl |
– | 14.8±1.5 14.7±1.4 |
14.4±1.4 14.2±1.4 |
Capillary Hb higher than venous |
| 10 | Patel et al10 | Hb (g/dL) | Hemocue 201 | – | 14.05±1.51 | 13.89±1.31 | Capillary Hb levels were found to be significantly higher than venous Hb levels |
| 11 | Singh et al21 | Hb (g/dL) | HemoControl DiaSpect Hemoglobin T |
– | 14.32±1.41 14.36±1.61 |
14.40±1.54 14.32±1.48 |
Differences not statistically significant (p>0.05) |
Abbreviations: Hb, hemoglobin; hct, hematocrit; SD, standard deviation; ELS, ear lobe sample; FS: finger-stick sample; VS, venous sample.