Table 2.
Mean bias (%) of laboratories’ results against RMP-defined targeta.
| Sample (target value) Assay Manufacturer Analytical System |
Sample A (15.5 ng/dl) | Sample B (30.0 ng/dl) | Sample C (402 ng/dl) | Sample D (498 ng/dl) | Assay Manufacturer Calibration bias | |||||
|---|---|---|---|---|---|---|---|---|---|---|
|
|
|
|
|
|
||||||
| nb | Mean bias in % (95% CI) | n | Mean bias in % (95% CI) | n | Mean bias in % (95% CI) | n | Mean bias in % (95% CI) | n | Mean bias in % (95% CI) | |
| Beckman Coulter | 20 | 13.1 (8.8 to 17.4) | ||||||||
| Access 2 | 6 | 73.1 (58.4 to 87.9) | 6 | 18.7 (10.1 to 27.4) | 6 | −8.8 (−11.2 to −6.3) | 6 | −3.9 (−7.5 to −0.4) | ||
| Unicel DxI 800 | 9 | 51.7 (32.9 to 70.4) | 11 | 15.8 (9.6 to 21.9) | 11 | −15.1 (−16.9 to −13.4) | 10 | −13.2 (−17.0 to −9.5) | ||
| Siemens | 75 | −1.2 (−4.5 to 2.2) | ||||||||
| ADVIA Centaur (XP, XPT) | 34 | 37.9 (26.2 to 49.6) | 39 | 21.3 (13.6 to 29.1) | 39 | −16.6 (−19.6 to −13.7) | 39 | −13.3 (−15.8 to −10.8) | ||
| Immulite 1000 | 4 | 13.5 (−7.7 to 34.7) | 4 | −17.6 (−26.8 to −8.4) | ||||||
| Immulite 2000 XPi | 20 | 9.8 (−1.2 to 20.7) | 20 | −24.8 (−28.3 to −21.4) | 21 | −22.1 (−25.6 to −18.6) | ||||
| Coat-A-Count | 4 | −2.6 (−9.5 to 4.3) | ||||||||
| Roche Diagnostics | 26 | 3.5 (0.1 to 6.9) | ||||||||
| Cobas e401,e601,e602 | 5 | −11.7 (−30.2 to 6.8) | 7 | 11.1 (−2.4 to 24.5) | 7 | 3.2 (−1.7 to 8.1) | 5 | 2.7 (−4.1 to 9.6) | ||
| MODULAR series | 9 | −17.8 (−29.7 to −5.8) | 11 | 18.3 (11.8 to 24.7) | 11 | 2.5 (0.7 to 4.3) | 10 | 1.5 (−2.0 to 5.0) | ||
| Elecsys | 8 | −2.1 (−11.5 to 7.3) | 7 | 18.7 (7.5 to 29.9) | 7 | 8.6 (3.4 to 13.7) | 8 | 4.3 (1.6 to 6.9) | ||
| LC-MS/MS | 5 | 25.5 (0.0 to 51.1) | 5 | 3.1 (−2.5 to 8.6) | 5 | 3.9 (−0.2 to 8.1) | 5 | 6.8 (−2.7 to 16.3) | 6 | 8.0 (0.5 to 15.4) |
| Ortho Clinical Diagnostics | 8 | −24.1 (−28.6 to −19.6) | ||||||||
a
Results from groups with 4 or more participants are reported.
b
n = number of participating laboratories.