Table 5.
Sensitivity and specificity for the combination of MTA and PA and for the combination of MTA and GCA for differentiating AD from controls in age group <65 years.
| N | Sens | Spec | Youden | |
|---|---|---|---|---|
| COMBINED MTA AND PA: | MTA ≥ 1, PA ≥ 1 | |||
| MTA and PA normal | 407 | Ref | Ref | Ref |
| MTA normal/PA abnormal | 252 | 0.77 | 0.72 | 0.49 |
| MTA abnormal/PA normal | 80 | 0.58 | 0.92 | 0.50 |
| MTA and PA abnormal | 308 | 0.90 | 0.94 | 0.84 |
| COMBINED MTA AND GCA: | MTA ≥ 1, GCA ≥ 1 | |||
| MTA and GCA normal | 465 | Ref | Ref | Ref |
| MTA normal/GCA abnormal | 194 | 0.69 | 0.81 | 0.50 |
| MTA abnormal/GCA normal | 91 | 0.57 | 0.92 | 0.49 |
| MTA and GCA abnormal | 297 | 0.86 | 0.94 | 0.80 |
A new variable using 4 levels was created, using only the cut-offs with a Youden index > 0.50 from Table 2. Sensitivity and specificity are calculated using cross tabulation. Youden index = (sensitivity + specificity) −1. Bold values are the combinations that showed the best differentiation. Sens, sensitivity; Spec, specificity.