Performance characteristics of optimised assays
| Assay | Cut off point (SDs above mean) | Mean specificity (CI) | Mean sensitivity (CI) | Mean positive predictive value (CI) | Mean negative predictive value (CI) |
|---|---|---|---|---|---|
| ACL, anticardiolipin; anti-β2gp1, anti-β2 glycoprotein 1; CI, confidence interval. | |||||
| Non-quantitative total ACL | 3 | 0.98 (0.96 to 1.00) | 0.55 (0.46 to 0.64) | 0.92 (0.87 to 0.97) | 0.79 (0.71 to 0.87) |
| Quantitative total ACL | 3 | 0.88 (0.82 to 0.94) | 0.59 (0.50 to 0.68) | 0.72 (0.64 to 0.80) | 0.80 (0.72 to 0.88) |
| IgG ACL | 4 | 0.98 (0.96 to 1.00) | 0.34 (0.26 to 0.42) | 0.88 (0.82 to 0.94) | 0.73 (0.65 to 0.81) |
| IgM ACL | 3 | 0.95 (0.91 to 0.99) | 0.34 (0.26 to 0.42) | 0.79 (0.72 to 0.86) | 0.71 (0.62 to 0.80) |
| Either IgG or IgM ACL | — | 0.95 (0.91 to 0.99) | 0.50 (0.41 to 0.59) | 0.85 (0.79 to 0.91) | 0.78 (0.70 to 0.86) |
| IgG anti-β2gp1 | 1 | 0.92 (0.87 to 0.97) | 0.43 (0.34 to 0.52) | 0.76 (0.68 to 0.83) | 0.75 (0.66 to 0.84) |
| IgM anti-β2gp1 | 4 | 0.97 (0.94 to 1.00) | 0.18 (0.11 to 0.25) | 0.8 (0.73 to 0.87) | 0.68 (0.59 to 0.77) |
| Either IgG or IgM anti-β2gp1 positive | — | 0.89 (0.83 to 0.95) | 0.48 (0.39 to 0.57) | 0.70 (0.62 to 0.78) | 0.76 (0.67 to 0.85) |