Table 7. Discriminative validity of the b- and i-ADL indices between HC, MCI, and AD.
| HC versus MCI | ||||||
| AUC (S.E.) | 95% CI | p-valuea | Optimal Cutoff | Sensitivity | Specificity | |
| Lawton & Brody Scale (Total) | 0.797 (0.03) | 0.726–0.868 | 22.5 | 67.6% | 79.5% | |
| i-ADL-DI | 0.858 (0.03) | 0.793–0.922 | 0.042 | 17.2% | 80.8% | 84.8% |
| i-ADL-CDI | 0.895 (0.02) | 0.840–0.950 | 0.002 | 3.8% | 80.8% | 91.1% |
| i-ADL-PDI | 0.724 (0.04) | 0.642–0.805 | 0.038 | 7.7% | 65.8% | 67.1% |
| Katz Index (Total) | 0.709 (0.04) | 0.629–0.796 | 6.5 | 52.7% | 87.3% | |
| b-ADL-DI | 0.736 (0.04) | 0.655–0.818 | 0.255 | 6.2% | 53.4% | 89.6% |
| b-ADL-CDI | 0.568 (0.04) | 0.477–0.660 | <0.001 | 2.1% | 13.7% | 100% |
| b-ADL-PDI | 0.711 (0.04) | 0.628–0.795 | 0.945 | 2.1% | 58.9% | 77.2% |
| MCI versus AD | ||||||
| AUC (S.E.) | 95% CI | p-valuea | Optimal Cutoff | Sensitivity | Specificity | |
| Lawton & Brody Scale (Total) | 0.719 (0.04) | 0.633–0.799 | 18.5 | 64.8% | 69.3% | |
| i-ADL-DI | 0.736 (0.04) | 0.654–0.818 | 0.349 | 44.1% | 70.4% | 74.3% |
| i-ADL-CDI | 0.805 (0.03) | 0.734–0.876 | 0.010 | 23.6% | 74.6% | 70.3% |
| i-ADL-PDI | 0.546 (0.04) | 0.452–0.641 | <0.001 | 8.8% | 66.2% | 41.1% |
| Katz Index (Total) | 0.593 (0.04) | 0.499–0.649 | 8.5 | 32.4% | 78.1% | |
| b-ADL-DI | 0.631 (0.04) | 0.539–0.722 | 0.099 | 18.3% | 46.5% | 80.8% |
| b-ADL-CDI | 0.648 (0.04) | 0.558–0.739 | 0.210 | 6.2% | 36.6% | 87.7% |
| b-ADL-PDI | 0.555 (0.04) | 0.460–0.649 | 0.197 | 10.4% | 45.1% | 64.4% |
| HC versus AD | ||||||
| AUC (S.E.) | 95% CI | p-valuea | Optimal Cutoff | Sensitivity | Specificity | |
| Lawton & Brody Scale (Total) | 0.932 (0.01) | 0.895–0.970 | 20.5 | 77.5% | 88.5% | |
| i-ADL-DI | 0.968 (0.01) | 0.938–0.998 | 0.010 | 30.5% | 90.1% | 96.2% |
| i-ADL-CDI | 0.990 (0.00) | 0.978–1.000 | <0.001 | 10.5% | 93.0% | 97.5% |
| i-ADL-PDI | 0.774 (0.03) | 0.698–0.849 | <0.001 | 7.7% | 71.8% | 67.1% |
| Katz Index (Total) | 0.787 (0.03) | 0.711–0.864 | 7.5 | 53.5% | 94.9% | |
| b-ADL-DI | 0.828 (0.03) | 0.759–0.897 | 0.039 | 10.4% | 60.6% | 93.7% |
| b-ADL-CDI | 0.718 (0.04) | 0.633–0.803 | 0.054 | 2.1% | 43.7% | 100% |
| b-ADL-PDI | 0.748 (0.04) | 0.668–0.829 | 0.155 | 10.4% | 45.1% | 94.0% |
b-ADL-DI: basic Activities of Daily Living—Disability Index; b-ADL-CDI: basic Activities of Daily Living—Cognitive Disability Index; b-ADL-PDI: basic Activities of Daily Living—Physical Disability Index; i-ADL-DI: instrumental Activities of Daily Living—Disability Index; i-ADL-CDI: instrumental Activities of Daily Living—Cognitive Disability Index; i-ADL-PDI: instrumental Activities of Daily Living—Physical Disability Index.
ap-values indicate the significant difference between the indices and the total scores of the Katz Index and Lawton Scale. Differences were calculated by comparing ROC curves with the method of DeLong et al. (1988) [89].