Table 3.
Diagnostic accuracy of mepacrine fluorescence and mepacrine release at different cutoff values compared with platelet ADP content as gold standard
| Cutoff (normalized median fluorescent intensity) | Sensitivity | Specificity | Positive predictive value | Negative predictive value | Cohen's ĸ | Positive likelihood ratio | Negative likelihood ratio |
|---|---|---|---|---|---|---|---|
| Mepacrine fluorescence | |||||||
| 67.8a | 70.6 (44.0‐89.7) | 88.5 (82.0‐93.3) | 42.9 (30.1‐56.6) | 96.1 (92.2‐98.1) | 0.46 | 6.1 (3.5‐10.7) | 0.3 (0.2‐0.7) |
| 71.2b | 76.5 (50.1‐93.2) | 82.7 (75.4‐86.6) | 35.1 (25.7‐45.9) | 96.6 (92.4‐98.60) | 0.39 | 4.4 (2.8‐6.9) | 0.3 (0.1‐0.7) |
| 84.3c | 94.1 (71.3‐99.9) | 50.4 (41.8‐59.0) | 18.8 (15.9‐22.2) | 98.6 (91.2‐99.8) | 0.16 | 1.9 (1.5‐2.3) | 0.1 (0.02‐0.8) |
| Mepacrine release | |||||||
| 43.5a | 35.3 (14.2‐61.7) | 87.8 (81.1‐92.7) | 26.1 (13.9‐43.6) | 91.7 (88.6‐94.1) | 0.20 | 2.9 (1.3‐6.3) | 0.7 (0.5‐1.1) |
| 51.3b | 76.5 (50.1‐93.2) | 76.3 (68.3‐83.1) | 28.3 (20.9‐37.0) | 96.4 (91.8‐98.4) | 0.30 | 3.2 (2.2‐4.8) | 0.3 (0.1‐0.7) |
aCutoff value derived from the 2.5th percentile of mepacrine fluorescence or release in healthy controls.
bCutoff value derived from the ROC curve.
cOptimal cutoff value as screening test for δ‐SPD.