Statistical Evaluation
| Diagnostic approach | PET | APOE | PET and APOE | PET or APOE |
|---|---|---|---|---|
| Sensitivity (%) | 92 | 75 | 67 | 100 |
| Specificity (%) | 89 | 56 | 100 | 44 |
| Test accuracy (%) | 90 | 63 | 87 | 67 |
| PPV (%) | 85 | 53 | 100 | 55 |
| NPV (%) | 94 | 77 | 82 | 100 |
PET = MCI patients with Alzheimer-suggestive PET scan at baseline were classified as test positive; APOE = MCI patients with APOE ε4–positive genotype were classified as test positive; PET and APOE = MCI patients with Alzheimer-suggestive PET scan and APOE ε4–positive genotype at baseline were classified as test positive; PET or APOE = MCI patients with Alzheimer-suggestive PET scan or APOE ε4–positive genotype were classified as test positive.