6000-300-000 5–3
5 – Performance and Limitations
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
6000-300-000 5-3
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
Parameter Range Max S. D.
GRAN (%) 38 – 79 3.2
LYMPH/MONO (%) 21 – 63 3.2
Accuracy
The performance of the QBC STAR system is based on data from venous blood samples collected in VACUTAINER
®
brand collection tubes containing K
2
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.
To Next Page