61
Osmo1
®
Single-Sample Micro-Osmometer User Guide
Appendix B
Performance characteristics
Definitions
Accuracy
Closeness of agreement between a test result and the accepted reference value (ISO 5725-1)
Repeatability
Precision under conditions where independent test results are obtained with the same method on identical test items
in the same laboratory by the same operator using the same equipment within short intervals of time (ISO 5725-1:1994)
Source: Harmonized Terminology Database at http://clsi.org
Characteristics
Reportable Range
0 to 2000 mOsm/kg H
2
O
Resolution
1 mOsm/kg H
2
O
Accuracy
1
(AI standards and reference solutions)
±2 mOsm/kg H
2
O from nominal value between 0 and 400 mOsm/kg H
2
O (1 SD)
±0.5% from nominal value between 400 and less than 1500 mOsm/kg H
2
O (1 SD)
±1% from nominal value from 1500 to 2000 mOsm/kg H
2
O (1 SD)
NOTE:
For more information about accuracy, see “Interpreting results” on page 8.
Accuracy with Clinical Samples
Accuracy of the Osmo1 was assessed by a method comparison study between the Osmo1 and the 3320 osmometer,
according to
CLSI EP09A-A3 Measurement Procedure Comparison
and
Bias Estimation Using Patient Samples;
Approved Guideline – Third Edition, 2013
. A total of 103 clinical sample types (serum, plasma, and urine) were tested
across three (3) Osmo1 and three (3) 3320 Osmometers.
The acceptance criteria for the method comparison study are shown below.
Passing-Bablok Regression
Slope:
1.0 ± 0.05, with 1.0 included within the 95% CI
Intercept:
0.0 ± 3.0 mOsm/kg, with 0.0 included in the 95% CI
Proportional Bias:
≤
5.0%
Constant Bias:
≤
3 mOsm/kg
1
Performance at Reference Conditions: 20 °C to 25 °C (68 °F to 77 °F); 40 to 60% relative humidity.