Table II.
Imprecision (CV) and bias for 35 analytes. Results obtained after storage of whole blood at 21°C was compared to baseline results.
| CV (%) |
Bias (%) |
Paired t-test p value†† | |||
|---|---|---|---|---|---|
| Analyte | CV† | Analytical‡/goal§ | Mean deviation (95% CI)|| | Goal¶ | |
| ALAT | 2.4 | 2.7/9.0 | − 1.7 (− 2.9;− 0.4) | 12.0** | 0.0034 |
| ALB | 1.5 | 0.9/3.2** | 0.2 (0;0.5) | 2.2** | 0.067 |
| AMYL | 1.1 | 2.4/5.9 | − 0.8 (− 1.2;− 0.3) | 8.0 | < 0.0001 |
| ATRYP | 2.9 | 0.9/4.5 | − 0.7 (− 1.5;0.1) | 6.5 | 0.12 |
| B12* | 6.4 | 6.4/7.5 | − 3.2 (− 5.6;− 0.8) | 17.7 | 0.015 |
| BASP | 1.2 | 2.2/4.8 | 0.2 (− 0.3;0.7) | 6.4 | 0.31 |
| BILI | 2.1 | 3.2/6.4** | 1.0 (0.2;1.9) | 10.0** | 0.11 |
| CA | 1.1 | 1.0/2.5** | 1.0 (0.7;1.3) | 2.0** | < 0.0001 |
| CHOL | 1.3 | 0.5/3.0** | 0.6 (0.2;1.1) | 4.0 | 0.0085 |
| CK | 1.4 | 0.8/5.7 | − 0.7 (− 1.3;− 0.1) | 11.5 | 0.0023 |
| CO2 | 3.4 | 5.0/6.0** | 1.2 (0.0;2.4) | 5.0** | 0.16 |
| CREA | 1.1 | 1.3/2.7** | − 0.1 (− 0.6;0.3) | 3.8** | 0.50 |
| CRP | 1.8 | 1.8/5.0** | 2.6 (− 0.5;5.7) | 5.0** | 0.046 |
| F-T3* | 2.4 | 2.2/7.5** | 0.8 (− 0.3;1.8) | 7.2 | 0.28 |
| F-T4* | 4.6 | 4.6/7.5** | 2.1 (0.3;3.9) | 3.6** | 0.039 |
| Fe | 3.7 | 1.6/6.7** | 6.8 (5.8;8.2) | 8.8 | < 0.0001 |
| FER* | 7.0 | 4.3/7.1 | − 1.1 (− 2.7;0.5) | 5.2 | 0.039 |
| FOL* | 20.5 | 6.6/12.0 | − 13.7 (− 19.1;− 8.3) | 19.2 | 0.0007 |
| GGT | 2.6 | 1.6/3.5 | − 0.8 (− 2.1;0.6) | 5.4 | 0.62 |
| HAPT | 1.7 | 1.4/5.1 | 0.1 (− 0.4;0.6) | 10.4 | 0.72 |
| HDL-C | 2.9 | 1.8/3.6 | 4.6 (3.7;5.4) | 5.2 | < 0.0001 |
| IgA | 2.1 | 1.3/2.7 | 1.9 (1.4;2.3) | 9.1 | < 0.0001 |
| IgG | 1.0 | 0.9/2.3 | 0.2 (− 0.2;0.5) | 4.3 | 0.75 |
| IgM | 1.5 | 2.5/4.5** | 1.7 (0.9;2.5) | 11.9 | 0.0001 |
| K | 2.9 | 0.8/2.4 | 1.2 (0.1;2.2) | 1.8 | 0.040 |
| LD | 4.5 | 3.1/5.0** | 1.0 (− 1.3;3.1) | 4.3 | 0.55 |
| Na | 0.4 | 0.7/1.0** | 0.3 (0.1;0.4) | 0.6** | 0.0003 |
| OROS | 1.5 | 0.9/5.7 | 0.8 (0.1;1.5) | 6.8 | 0.017 |
| P | 9.0 | 1.8/4.3 | − 11.2 (− 12.4;− 10.0) | 3.2 | < 0.0001 |
| PSA* | 3.4 | 3.4/9.1 | − 0.4 (− 2.0;1.2) | 18.7 | 0.083 |
| TGLY | 2.0 | 1.0/5.3** | − 0.9 (− 1.7;− 0.1) | 5.4** | 0.018 |
| TRANS | 1.5 | 0.9/2.3 | 1.8 (1.4;2.2) | 2.6** | < 0.0001 |
| TSH* | 9.2 | 4.9/9.7 | 6.0 (3.4;8.7) | 7.8 | 0.0040 |
| URATE | 1.6 | 1.3/4.3** | 1.5 (0.9;2.1) | 4.8** | < 0.0001 |
| UREA | 1.0 | 1.9/6.2 | − 0.2 (− 0.6;0.2) | 5.5 | 0.072 |
Analysis performed on Advia Centaur XP using whole blood in serum tubes. For the other analytes analysis was performed on Architect c8000 using whole blood in lithium-heparin tubes.
CV calculation based on measurements at baseline and after 10 h of storage.
Annual (2011) average CV of laboratory routine quality control samples.
CV goals used in evaluating analytical variation in laboratory routine quality control. Goals were generally based on biological variation from http://westgard.com/biodatabase1.htm and calculated as described by Fraser et al. [18].
denotes goals where empirically based modifications to the three stated levels of performance were used.
Mean deviation % between baseline and 10-h values and 95% confidence interval (shown as confidence limits).
Bias goals used in evaluating systematic differences in laboratory routine quality control.
See §CV goals for further details.
p-values for testing baseline values against values obtained after 10 h of storage of whole blood.