Table 2. Comparison of ‘new’ and ‘current’ biomarkers by logistic regression.
| Statistic | New Biomarkers (n) | Current biomarker (n) | New + Current | |||
| T-Tf (WB) (99) | Tf-1 (87) | Tf-β2 (87) | T-Tf ELISA (99) | T-tau (95) | T-Tf (WB)+T-tau | |
| Area under ROC (95%CI) | 0.90 (0.85–0.94) | 0.86 (0.80–0.92) | 0.82 (0.76–0.89) | 0.80 (0.73–0.88) | 0.78 (0.71–0.85) | 0.93 (0.89–0.97) |
| Sensitivity (95%CI) | 85.9 (77.1–91.8) | 85.1 (75.4–91.5) | 85.1 (75.4–91.5) | 85.9 (77.1–91.8) | 85.3 (76.2–91.4) | 85.3 (76.2–91.4) |
| Specificity (95%CI) | 71.6 (59.1–81.7) | 65.7 (53.0–76.6) | 64.2 (51.5–75.3) | 64.1 (51.0–75.4) | 48.4 (35.9–61.2) | 87.5 (76.3–94.1) |
| Positive LR (95%CI) | 3.0 (2.1–4.5) | 2.5 (1.8–3.5) | 2.4 (1.7–3.3) | 2.4 (1.7–3.3) | 1.7 (1.3–2.1) | 6.8 (3.5–13.1) |
| Negative LR (95%CI) | 0.2 (0.1–0.3) | 0.2 (0.1–0.4) | 0.2 (0.1–0.4) | 0.2 (0.1–0.4) | 0.3 (0.2–0.5) | 0.2 (0.1–0.3) |
| PPV (%) (95%CI) | 81.7 (72.7–88.4) | 76.3 (66.4–84.1) | 75.5 (65.6–83.4) | 78.7 (69.6–85.8) | 71.1 (61.7–79.0) | 91.0 (82.6–95.8) |
| NPV (%) (95%CI) | 77.4 (64.7–86.7) | 77.2 (63.8–86.8) | 76.8 (63.3–86.6) | 74.5 (60.7–84.9) | 68.9 (53.2–81.4) | 80.0 (68.4–88.3) |
| AIC | 0.81 | 0.96 | 1.03 | 1.06 | 1.23 | 0.70 |
| Accuracy | 80.1 | 76.6 | 76 | 77.3 | 70.4 | 86.2 |
Note: Accuracy was defined as true positives + true negatives/total number tested.
Positive/negative LR results are robust to variations in prevalence rates between the study and overall population, and are provided in addition to PPV/NPV that are highly dependent on the population tested.