QBC Diagnostics Star - Accuracy

QBC STAR™ System User’s Manual
5–2 L–000867(A)
In a separate precision study, intra- and inter-run precision were assessed using a dual level QBC Control (#424304). The
controls were assayed on multiple days at three sites using
QBC STAR
tubes and the
QBC STAR
system. The results of this
study are presented in the table below.
Control Precision
Accuracy
The performance of the
QBC STAR
system is based on data from venous blood samples collected in VACUTAINER
®
brand col-
lection tubes containing K
3
EDTA anticoagulant. Venous blood samples provide a more stable test system than capillary blood
for comparing results from multiple methods. While skin puncture samples provide clinically relevant results, they are subject
to more variation due to the nature of the sampling technique.
Two
QBC STAR
tubes were prepared on each of approximately 323 blood samples and analyzed on both the
QBC STAR
system
and either the Coulter
®
STKS or Sysmex K1000 analyzers*. The correlation coeffi cients for the WBC, Gran, L/M, Hct, and Hgb,
and PLT parameters were 0.95 or greater. Complete statistical results are presented below.
Control Level 1 Control Level 2
Intra-Day* Intra-Run** Intra-Day* Intra-Run**
Parameter
Site
Mean
Value
%CV df %CV df
Mean
Value
%CV df %CV df
HCT (%)
BD
POL #1
POL #2
30.46
30.93
30.71
0.28
1.37
0.73
10
10
9
1.58
1.66
1.12
20
20
19
34.87
35.27
34.65
0.00
1.22
0.00
10
10
9
0.95
2.26
1.25
20
20
19
HGB (g/dL)
BD
POL #1
POL #2
10.07
10.16
10.22
0.00
1.49
0.82
10
10
9
1.52
1.48
1.00
20
20
19
11.65
11.69
11.66
0.00
1.06
0.14
10
10
9
0.99
2.34
1.18
20
20
19
PLT (x 10
9
/L)
BD
POL #1
POL #2
443.33
382.78
459.37
0.00
4.06
0.00
10
10
9
10.64
4.02
11.08
20
20
19
194.55
163.48
204.18
6.50
2.08
0.00
10
10
9
18.86
3.31
12.84
20
20
19
WBC (x
10
9
/L)
BD
POL #1
POL #2
9.18
9.74
9.32
0.00
0.00
4.33
10
10
9
5.83
7.22
5.17
20
20
19
21.31
21.67
19.88
0.00
1.03
5.61
10
10
9
7.45
5.40
9.57
20
20
19
GRAN (x
10
9
/L)
BD
POL #1
POL #2
4.80
5.27
5.06
0.00
0.00
2.89
10
10
9
8.96
8.79
6.70
20
20
19
5.51
6.23
5.37
4.82
2.92
0.00
10
10
9
5.25
8.31
8.68
20
20
19
LYMPH/
MONO
(x 10
9
/L)
BD
POL #1
POL #2
4.38
4.48
4.26
1.49
0.00
5.35
10
10
9
5.62
6.52
6.56
20
20
19
15.81
15.44
14.52
0.00
1.75
7.63
10
10
9
8.96
7.59
12.61
20
20
19
*Variability between runs during the same days
** Variability between tubes on the same run during the same day (error)
df = degrees of freedom
0.00 denotes a negative variance estimate