Drucker Diagnostics Paralens Advance User Manual
Page 50
*Products of Coulter Electronics,
Hialeah, FL
7.4.2 Accuracy
The performance of AccuTubes with the QBC
Autoread Plus system is based on data from venous
blood samples collected in Vacutainer™ brand collec-
tion tubes containing K
3
EDTA anti coagulant. Venous
blood samples provide a more stable test system than
capillary blood for comparing results from multiple
methods. While skin puncture samples provide clin-
ically relevant results, they are subject to more varia-
tion due to the nature of the sampling technique.
Approximately 290 blood samples were analyzed
on both the QBC Autoread Plus System with
AccuTubes and Coulter™ Hematology analyzers
(S Plus, S Plus IV, STKS, STKR)*. The correlation
coefficients for the WBC, Gran, L/M, HCT,
and HB parameters were 0.95 or greater. The
correlation coefficient for the PLT parameter was
0.93. Complete statistical results are presented
below.
The hematocrit results shown above reflect the
calibration methods of the Coulter analyzers
used in the correlation study. The QBC Autoread
Plus software has been calibrated to match the
international reference standard for microhematocrit
(MHCT) technology.
13
The data shown in the
table below were obtained by comparing the
QBC Autoread Plus/AccuTube results against the
microhematocrit reference method.
7-4
Parameter
Correlation
Coefficient
Slope
Intercept
QBC Mean
Cell Counter
Mean
Range of
Values
Number
of
Samples
Hematocrit (%)
0.993
0.960
2.587
35.7
34.5
13.8 - 60.2
294
Hemoglobin (g/dL)
0.994
0.992
0.050
11.7
11.7
5.5 - 19.0
293
Platelet (× 10
9
/L)
0.931
0.926
16.463
267
271
29 - 843
278
WBC (× 10
9
/L)
0.978
1.045
–0.239
10.8
10.5
2.1 - 81.5
282
Granulocyte (× 10
9
/L)
0.985
1.071
–0.458
7.9
7.8
0.7 - 71.0
277
Lymph/Mono (× 10
9
/L)
0.957
0.826
0.614
2.9
2.8
0.2 - 76.9
280
*Products of Coulter Electronics, Hialeah, FL
Parameter
Correlation
Coefficient
Slope
Intercept
QBC Mean
Cell Counter
Mean
Range of
Values
Number
of
Samples
Hematocrit (%)
0.996
1.003
-0.111
34.4
34.4
17.5 - 53.1
120