Table 2. SRL performance based on JMA external quality assessment and SRL internal quality control system (unit, %).
| Analyte | Performance | Measurement performance by SRL during observation period | Proposed TE Criteria | Application to new data | (For reference) CAP TE Criteria |
|||||||||||||||
| Year | Median (LL, UL of 80% CL) |
Acceptable | Borderline | Unacceptable |
Performance in 2011 |
Evaluation by proposed TE criteria in 2011 |
||||||||||||||
| 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | |||||||||
| Total cholesterol | Accuracy (%bias) | 0.19 | −0.48 | 0.27 | 0.34 | −0.15 | −0.06 | 0.13 | −0.82 | −1.31 | −1.45 | −0.82 | −0.66 | −0.32 (−0.74, 0.04) | 0.19 | |||||
| Precision (CV%) | 1.7 | 1.6 | 1.3 | 1.1 | 1.6 | 1.0 | 1.2 | 1.0 | 0.7 | 0.8 | 0.7 | 0.7 | 1.1 (0.9, 1.3) | 0.8 | ||||||
| Total Error (%) | 3.6 | 3.6 | 2.7 | 2.5 | 3.3 | 2.1 | 2.4 | 2.7 | 2.7 | 3.0 | 2.2 | 2.0 | 2.7 (2.5, 2.9) | <2.9 | 2.9–5.7 | ≥5.8 | 1.8 | acceptable | 5.0 | |
| HDL cholesterol | Accuracy (%bias) | −0.19 | −1.57 | −1.09 | 1.60 | 0.02 | −0.33 | 0.70 | 1.29 | −2.89 | −0.90 | −0.17 | −0.68 | −0.26 (−0.79, −0.08) | −2.00 | |||||
| Precision (CV%) | 2.4 | 1.8 | 1.6 | 2.1 | 2.0 | 1.5 | 1.6 | 2.3 | 1.5 | 1.8 | 1.3 | 1.7 | 1.8 (1.6, 1.9) | 1.7 | ||||||
| Total Error (%) | 4.9 | 5.1 | 4.2 | 5.7 | 4.0 | 3.2 | 3.8 | 5.7 | 5.8 | 4.4 | 2.7 | 4.0 | 4.3 (4.0, 5.0) | <5.0 | 5.0–9.9 | ≥10.0 | 5.3 | fairly acceptable | 15.0 | |
| LDL cholesterol | Accuracy (%bias) | — | — | — | — | — | — | — | — | −0.39 | 1.95 | −2.45 | 0.50 | 0.06 (−1.42, 1.23) | 0.63 | |||||
| Precision (CV%) | — | — | — | — | — | — | — | — | 1.2 | 2.0 | 0.9 | 1.4 | 1.3 (1.1, 1.7) | 1.1 | ||||||
| Total Error (%) | — | — | — | — | — | — | — | — | 2.7 | 5.9 | 4.2 | 3.2 | 3.7 (3.0, 5.0) | <5.0 | 5.0–10.0 | ≥10.1 | 2.8 | acceptable | 15.0 | |
| Triglycerides | Accuracy (%bias) | 1.91 | −0.58 | −1.34 | 0.37 | 1.56 | −0.12 | −0.36 | 0.00 | −0.97 | −1.10 | −1.86 | −1.67 | −0.47 (−1.04, −0.06) | −0.18 | |||||
| Precision (CV%) | 1.8 | 2.3 | 2.4 | 2.6 | 2.3 | 1.5 | 1.4 | 2.3 | 1.0 | 1.0 | 1.1 | 1.2 | 1.7 (1.3, 2.3) | 1.6 | ||||||
| Total Error (%) | 5.5 | 5.2 | 6.1 | 5.5 | 6.2 | 3.0 | 3.1 | 4.6 | 2.9 | 3.1 | 4.0 | 4.0 | 4.3 (3.6, 5.3) | <5.3 | 5.3–10.4 | ≥10.5 | 4.4 | acceptable | 12.5 | |
| Total protein | Accuracy (%bias) | −0.27 | −0.12 | 0.46 | −0.24 | −0.14 | −0.28 | 0.19 | −0.07 | −0.39 | 1.59 | −0.58 | 1.78 | −0.13 (−0.26, 0.06) | 3.21 | |||||
| Precision (CV%) | 1.4 | 1.0 | 0.9 | 1.5 | 2.0 | 1.6 | 1.4 | 1.5 | 1.5 | 1.6 | 1.0 | 1.3 | 1.5 (1.4, 1.5) | 1.3 | ||||||
| Total Error (%) | 3.0 | 2.1 | 2.2 | 3.2 | 4.1 | 3.4 | 2.9 | 3.0 | 3.3 | 4.7 | 2.5 | 4.3 | 3.1 (3.0, 3.4) | <3.4 | 3.4–6.6 | ≥6.7 | 5.8 | fairly acceptable | 5.0 | |
| Albumin | Accuracy (%bias) | −2.43 | −0.75 | 0.45 | −1.12 | 0.64 | 0.12 | −0.06 | 0.11 | 1.05 | −0.28 | −1.14 | 0.46 | 0.03 (−0.52, 0.29) | 5.19 | |||||
| Precision (CV%) | 1.7 | 1.3 | 2.0 | 1.8 | 1.9 | 1.2 | 1.6 | 1.1 | 0.9 | 1.2 | 1.0 | 1.2 | 1.3 (1.2, 1.6) | 1.0 | ||||||
| Total Error (%) | 5.8 | 3.3 | 4.4 | 4.6 | 4.4 | 2.5 | 3.2 | 2.3 | 2.8 | 2.6 | 3.1 | 2.8 | 3.1 (2.8, 3.8) | <3.8 | 3.8–7.6 | ≥7.7 | 7.1 | fairly acceptable | 5.0 | |
| Creatinine | Accuracy (%bias) | −2.24 | 1.93 | −0.08 | −0.34 | 0.15 | 0.19 | −0.76 | −0.55 | −0.76 | −1.25 | −0.54 | −4.18 | −0.55 (−0.76, −0.21) | −2.77 | |||||
| Precision (CV%) | 1.5 | 2.6 | 3.7 | 2.0 | 1.9 | 2.3 | 1.8 | 2.3 | 1.7 | 2.3 | 1.3 | 1.8 | 2.0 (1.8, 2.3) | 1.7 | ||||||
| Total Error (%) | 5.1 | 7.1 | 7.2 | 4.3 | 3.9 | 4.8 | 4.3 | 5.0 | 4.1 | 5.8 | 3.1 | 7.7 | 4.9 (4.3, 5.5) | <5.5 | 5.5–10.8 | ≥10.9 | 6.1 | fairly acceptable | 7.5 | |
| Glucose | Accuracy (%bias) | 0.42 | −0.58 | −0.39 | −0.31 | 0.17 | −0.06 | 0.76 | 0.53 | −0.83 | −0.04 | 0.01 | −0.74 | −0.05 (−0.35, 0.09) | −0.47 | |||||
| Precision (CV%) | 1.4 | 1.0 | 1.7 | 1.2 | 1.4 | 1.4 | 1.4 | 1.5 | 1.5 | 0.8 | 0.8 | 1.0 | 1.4 (0.8, 0.8) | 1.1 | ||||||
| Total Error (%) | 3.1 | 2.5 | 3.7 | 2.7 | 3.0 | 2.7 | 3.5 | 3.5 | 3.8 | 1.6 | 1.6 | 2.7 | 2.9 (2.7, 3.3) | <3.3 | 3.3–6.5 | ≥6.6 | 2.6 | acceptable | 5.0 | |
| γ-GT (γ-GTP) | Accuracy (%bias) | 0.74 | −0.01 | −0.24 | 0.82 | 0.37 | −0.13 | −0.48 | −0.83 | −1.50 | 0.45 | −0.75 | −1.04 | −0.19 (−0.62, 0.18) | −1.39 | |||||
| Precision (CV%) | 1.8 | 1.8 | 1.6 | 1.7 | 2.3 | 1.3 | 2.0 | 2.1 | 1.9 | 2.0 | 2.5 | 2.1 | 2.0 (1.8, 2.1) | 1.8 | ||||||
| Total Error (%) | 4.2 | 3.5 | 3.4 | 4.2 | 4.8 | 2.7 | 4.4 | 5.0 | 5.2 | 4.4 | 5.7 | 5.2 | 4.4 (4.2, 4.9) | <4.9 | 4.9–9.7 | ≥9.8 | 4.9 | acceptable | 7.5 | |
| Uric acid | Accuracy (%bias) | 0.21 | −0.59 | −0.43 | 0.25 | −0.26 | 0.81 | −0.44 | 0.88 | −0.44 | −0.56 | 0.31 | 1.26 | −0.03 (−0.44, 0.28) | 1.11 | |||||
| Precision (CV%) | 2.1 | 2.1 | 1.4 | 1.5 | 1.4 | 1.4 | 1.8 | 1.5 | 1.6 | 1.1 | 1.3 | 1.6 | 1.5 (1.1, 1.1) | 1.1 | ||||||
| Total Error (%) | 4.4 | 4.8 | 3.2 | 3.2 | 3.1 | 3.6 | 4.0 | 3.8 | 3.6 | 2.7 | 2.9 | 4.4 | 3.6 (3.2, 3.9) | <3.9 | 3.9–7.7 | ≥7.8 | 3.3 | acceptable | 8.5 | |
| Urea nitrogen | Accuracy (%bias) | −1.69 | 0.16 | 0.25 | 1.74 | −0.17 | 0.75 | −0.33 | 0.69 | −2.86 | — | — | 1.58 | 0.21 (−0.25, 0.69) | not assayed | |||||
| Precision (CV%) | 1.3 | 1.2 | 1.2 | 1.7 | 1.8 | 1.1 | 1.9 | 1.4 | 1.5 | — | — | 1.5 | 1.5 (1.3, 1.6) | not assayed | ||||||
| Total Error (%) | 4.3 | 2.6 | 2.7 | 5.1 | 3.7 | 3.0 | 4.1 | 3.4 | 5.8 | — | — | 4.5 | 3.9 (3.3, 4.4) | <4.4 | 4.4–8.7 | ≥8.8 | not assayed | 4.5 | ||
| AST (GOT) | Accuracy (%bias) | 3.03 | −0.43 | 0.21 | −0.07 | 1.37 | 0.59 | −0.60 | 0.25 | −1.25 | 0.51 | 0.71 | 0.64 | 0.38 (0.07, 0.62) | −0.37 | |||||
| Precision (CV%) | 1.7 | 1.8 | 1.3 | 1.1 | 2.1 | 1.4 | 1.9 | 1.5 | 2.2 | 1.5 | 1.6 | 2.2 | 1.7 (1.5, 1.9) | 1.8 | ||||||
| Total Error (%) | 6.3 | 4.0 | 2.7 | 2.3 | 5.5 | 3.4 | 4.4 | 3.3 | 5.6 | 3.5 | 3.8 | 5.0 | 3.9 (3.4, 4.6) | <4.6 | 4.6–9.2 | ≥9.3 | 3.9 | acceptable | 10.0 | |
| ALT (GPT) | Accuracy (%bias) | 2.81 | −0.22 | 0.38 | −1.43 | −0.08 | 1.48 | 1.06 | −0.64 | −1.47 | 0.95 | 0.88 | 0.37 | 0.38 (−0.15, 0.92) | −1.12 | |||||
| Precision (CV%) | 1.4 | 1.7 | 1.4 | 1.4 | 2.3 | 1.5 | 2.3 | 2.2 | 2.2 | 1.6 | 1.8 | 2.2 | 1.8 (1.6, 2.2) | 2.3 | ||||||
| Total Error (%) | 5.5 | 3.6 | 3.2 | 4.2 | 4.5 | 4.4 | 5.5 | 4.9 | 5.8 | 4.1 | 4.4 | 4.7 | 4.5 (4.3, 4.8) | <4.8 | 4.8–9.5 | ≥9.6 | 5.6 | fairly acceptable | 10.0 | |
| HbA1c | Accuracy (%bias) | — | — | −0.39 | 0.52 | 0.01 | 2.25 | 1.01 | 1.28 | −0.34 | −1.08 | −0.14 | −0.26 | −0.07 (−0.30, 0.52) | 0.12 | |||||
| Precision (CV%) | — | — | 1.1 | 1.1 | 1.0 | 1.2 | 1.1 | 1.0 | 1.4 | 1.2 | 1.4 | 1.6 | 1.2 (1.1, 1.3) | 2.0 | ||||||
| Total Error (%) | — | — | 2.5 | 2.7 | 2.0 | 4.6 | 3.2 | 3.2 | 3.1 | 3.4 | 2.9 | 3.4 | 3.1 (2.8, 3.3) | <3.3 | 3.3–6.5 | ≥6.6 | 4.0 | fairly acceptable | ||
Accuracy as an index of systematic error is expressed as %bias calculated based on JMA criteria.
Precision as an index of random error is expressed as CV calculated from SRL internal quality control data.
Total error is calculated as the sum of accuracy and precision, ie, absolute value of %bias + 1.96 × CV.
Abbreviations: JMA, Japan Medical Association; CAP, College of American Pathologists; TE, total error; LL, lower limit; UL, upper limit; CL, confidence limit; HDL, high-density lipoprotein; LDL, low-density lipoprotein; γ-GT (γ-GTP), γ-glutamyl transpeptidase; AST (GOT), aspartate aminotransferase; ALT (GPT), alanine aminotransferase; HbA1c, hemoglobin A1c.