Limitations of the method
a) The measurement needs to be started no later than 10 minutes after filling the
microcuvette.
b) Mixing samples for an extended period can produce increased oxygen pressure and
viscosity that may give falsely results.
c) If “HHH” is displayed, the result exceeds the measuring range of the system.
d) Values above 23.5 g/dL (235 g/L, 14.6 mmol/L) must be confirmed using a suitable
laboratory method.
e) Following substances have not been found to interfere: Acetaminophen (20 mg/dL),
ascorbic acid (3 mg/dL), conjugated bilirubin (40 mg/dL), unconjugated bilirubin
(20 mg/dL), creatinine (30 mg/dL), ibuprofen (40 mg/dL), leukocytes (600 x 10
9
/L),
lipemia (intralipid 4000 mg/L, triglycerides approximately 1000 mg/dL), salicylic acid
(50 mg/dL), tetracycline (20 mg/dL), trombocytes (2100 x 10
9
/L), urea (500 mg/dL),
uric acid (20 mg/dL). The highest concentration or percentages tested is referred to in
brackets. Intereference studies have been performed according to NCCLS Document
EP-7
4
.
f) pH values between 6.3-9.0 do not interfere with the system.
g) Sulfhemoglobin is not measured with this method.
Expected values
2
Children
11.0-14.0 g/dL (110-140 g/L, 6.8-8.7 mmol/L)
Women
12.0-15.0 g/dL (120-150 g/L, 7.4-9.3 mmol/L)
Men
13.0-17.0 g/dL (130-170 g/L, 8.1-10.5 mmol/L)
Children, 2 years to teenage, gradually increase to adult values.
Due to a wide range of conditions (dietary, geographical, etc) which affect normal val-
ues, it is recommended that each laboratory establish its own normal range.
Specific performance characteristics
Within-run and Total precision
Within-run precision was determined according to the NCCLS Document EP5-A
5
.
The results given below in ”Within-run precision” and ”Total precision” come from
1
batch of HemoCue Hb 201 Microcuvettes and 5 HemoCue Hb 201
+
Analyzers. No
recalibration was performed during the analyzing period. Commercially available con-
trols at 2 different levels were used. The hemoglobin concentration was measured in
duplicate twice a day, morning and afternoon, during 20 consecutive days.
Within-run Precision
Total Precision
Control
level
N
x–
g/dL
SD
g/dL
CV
%
SD
g/dL
CV
%
1
400
7.70
0.057
0.74
0.100
1.30
2
400
15.33
0.078
0.51
0.109
0.71
Accuracy
The results of the comparison studies between the HemoCue Hb 201 system and the
International Council for Standardization in Haematology method (ICSH)
3
are sum-
marized in the table below. The study was performed on four HemoCue Hb 201
+
Analyzer which had not been recalibrated during the study period.
Study
N
Min
g/dL
Max
g/dL
Regression line
Correlation
coefficient (r)
1
498
4.1
20.5
Y = 1.009X – 0.008
0.998
2
103
9.0
17.7
Y = 0.971X + 0.584
0.934
1 = ICSH (Cyanmethemoglobin method), venous EDTA blood, multicenter study
2 = ICSH (Cyanmethemoglobin method), capillary blood