Table 1: Variability in hematological parameters from two different brands of K3EDTA vacuum tubes.

Comprehensive results
Hematological parameters (unit)Desirable Bias (%)Tube ITube IIMean % difference
( 𝑃 value)

RBC* (×106/ 𝜇 L)1.75.12 ± 0.41 [4.28–5.71]5.08 ± 0.40 [4.31–5.64]0.8 (<0.01)
HCT* (%)1.743.5 ± 3.1 [37.9–49.4]42.9 ± 3.1 [36.9–49.1]1.4 (< 0.01)
HGB* (g/dL)1.814.31 ± 1.13 [12.80–16.70]14.29 ± 1.15 [12.70–16.70]0.1 (0.56)
MCV** (fL)1.285.9 ± 6.7 [81.4–87.6]85.6 ± 6.7 [81.1–87.0]0.4 (< 0.01)
MCHC** (pg)1.428.6 ± 3.1 [26.6–29.3]28.9 ± 3.2 [26.6–29.3]−1.0 (0.87)
RDW** (%)1.712.6 ± 1.1 [12.4–13.6]12.6 ± 1.1 [12.4–13.7]0.0 (0.94)
WBC* (×103/ 𝜇 L)5.65.80 ± 1.08 [4.00–7.91]5.88 ± 1.11 [3.94–8.01]−1.4 (0.15)
LYMPHO* (×103/ 𝜇 L)7.41.90 ± 0.66 [0.81–3.33]1.92 ± 0.70 [0.78–3.64]−1.0 (0.54)
MONO* (×103/ 𝜇 L)13.20.35 ± 0.13 [0.17–0.69]0.36 ± 0.12 [0.21–0.63]−2.9 (0.27)
NEU* (×103/ 𝜇 L)9.03.35 ± 0.73 [2.38–4.93]3.37 ± 0.72 [2.48–5.09]−0.6 (0.36)
EOS* (×103/ 𝜇 L)19.80.15 ± 0.10 [0.02–0.36]0.15 ± 0.10 [0.02–0.37]0.0 (0.75)
BASO* (×103/ 𝜇 L)15.40.041 ± 0.016 [0.020–0.070]0.044 ± 0.020 [0.010–0.090]−7.3 (0.38)
LUC* (×103/ 𝜇 L)NA0.154 ± 0.048 [0.070–0.260]0.158 ± 0.054 [0.070–0.270]−2.6 (0.41)
PLT* (×103/ 𝜇 L)5.9298.3 ± 61.5 [228.0–431.0]292.7 ± 56.3 [224.0–407.0]1.9 (0.02)
MPV* (fL)2.38.45 ± 0.69 [7.30–9.80]8.75 ± 0.84 [7.40–10.6]−3.6 (< 0.01)
PDW** (%)1.454.4 ± 6.6 [48.9–57.2]51.8 ± 10.4 [48.8–58.6]4.8 (< 0.01)

*Normal distribution; the values were mean ± standard deviation (range: minimum-maximum); 𝑃 value represents the significance by paired Student’s 𝑡 -test.
**Nonnormal distribution; the values were median ± standard deviation (5th–95th percentiles); 𝑃 value represents the significance by Wilcoxon ranked-pairs test.
The bold 𝑃 values are statistically significant ( 𝑃 < 0 . 0 5 ), and bold mean % differences represent clinically significant variations, when compared with desirable bias [15].
NA: not available [15].
Tube I: 4.5 mL Labor Import lot 20100505 (concentration of K3EDTA inside the tube is not made known by Shandong Weigao Group Medical Polymer, Weihai, China).
Tube II: 1.2 mL S-Monovette lot 0092201 with 1.6 mg K3EDTA (Sarstedt, Nümbrecht, Germany).