Drucker Diagnostics Paralens Advance - Manual (Page 62)

A-2.4.2 Accuracy
Performance of the Autoread Plus analyzer with
QBC standard tubes is typical of the family of QBC
hematology analyzers exhibiting the performance
shown in Table A-2-2 below.
The MCHC value displayed by the Autoread
Plus analyzer is electronically calculated from
the hemoglobin and hematocrit by the standard
formula of derivation. MCHC was compared with
values obtained by a Coulter analyzer and a
manual method as reference. The correlation
study involved 196 venous specimens. Due to the
numerically narrow range of the MCHC parameter,
neither of the automated test procedures (QBC
analyzer or Coulter analyzer) correlated perfectly
with the reference method; however, MCHC by the
QBC analyzer correlated as well with the reference
method as the Coulter analyzer (Table A-2-3).
A-2-4
Table A-2-2
CORRELATION DATA: QBC SYSTEM HCT, HB, PLT, AND WBC
Parameter
Specimen
(Reference Method)
n=
Range of
Reference
Values
Correlation
Coefficient
Slope Intercept
HCT (%)
Venous
(Microhematocrit) 13
200 16.5 - 56.6 0.9884 0.9952 –0.3655
Capillary
(Microhematocrit) 13
100 34.0 - 50.7 0.9450 1.0000 0.0027
HB (g/dl)
Venous
(Cyanmethemoglobin) 14
206 7.0 - 17.8 0.9905 1.0007 –0.0477
Capillary
(Cyanmethemoglobin) 14
112 10.1 - 18.2 0.9590 0.9888 –0.05077
PLT
(× 10
9
/l)
Venous
(See Note 1)
492 9 - 733 0.9056 0.9744 –8.2440
Venous
(Phase Microscopy)
101 2 - 869 0.9326 1.0260 –0.0583
Capillary
(UF-100)
99 146 - 383 0.7129 0.9903 0.1430
WBC
(× 10
9
/l)
Venous
(See Note 2)
385 1.8 - 32.0 0.9825 0.9613 0.5059
Capillary
(Coulter ZBI)
100 3.9 - 12.7 0.8652 0.9870 –0.0592
Notes to Table A-2-2:
1. Reference methods – ULTRA-FLO 100 Platelet analyzer and Coulter Model S+ analyzer
2. Reference methods – Coulter ZBI analyzer and Coulter Model S+ analyzer
Table A-2-3
CORRELATION MATRIX: MCHC (196 Specimens)
QBC Coulter Reference
QBC 1.0
Coulter 0.6762 1.0
Reference 0.6727 0.6859 1.0