Table 4.
Sensitivity and specificity of DSR in the discrimination of Alzheimer’s disease and mild cognitive impairment and positive predictive values (PPV) and negative predictive values (NPV) at different base rates
|
Alzheimer’s disease |
PPV/NPV at different base rate |
||||||
|
DSR cutoff |
Sensitivity |
Specificity |
10% |
20%% |
30% |
40% |
50% |
| 6.50 |
0.992 |
0.907 |
0.54/1.00 |
0.73/1.00 |
0.60/1.00 |
0.64/0.99 |
0.68/0.99 |
| 7.50 |
0.988 |
0.907 |
0.54/1.00 |
0.73/1.00 |
0.82/0.99 |
0.88/0.99 |
0.91/0.99 |
| 9.00 |
0.988 |
0.918 |
0.57/1.00 |
0.75/1.00 |
0.84/0.99 |
0.89/0.99 |
0.92/0.99 |
| *10.50 |
0.980 |
0.938 |
0.63/1.00 |
0.80/1.00 |
0.87/0.99 |
0.91/0.98 |
0.94/0.98 |
| 11.50 |
0.972 |
0.938 |
0.63/1.00 |
0.80/1.00 |
0.87/0.99 |
0.91/0.98 |
0.94/0.97 |
| 12.50 |
0.952 |
0.959 |
0.72/1.00 |
0.85/0.99 |
0.91/0.98 |
0.94/0.97 |
0.96/0.95 |
| 14.00 |
0.923 |
0.969 |
0.77’0.99 |
0.88/0.98 |
0.93/0.97 |
0.95/0.95 |
0.97/0.93 |
|
Mild cognitive impairment |
PPV/NPV at different base rate |
||||||
|
DSR cutoff |
Sensitivity |
Specificity |
10% |
20% |
30% |
40% |
50% |
| 12.50 |
0.952 |
0.739 |
0.29/0.99 |
0.48/0.98 |
0.60/0.97 |
0.71/0.96 |
0.78/0.94 |
| 14.00 |
0.923 |
0.761 |
0.30/0.99 |
0.49/0.98 |
0.62/0.96 |
0.72/0.94 |
0.79/0.91 |
| *15.50 |
0.899 |
0.799 |
0.33/0.99 |
0.53/0.97 |
0.66/0.95 |
0.75/0.92 |
0.82/0.89 |
| 16.50 |
0.879 |
0.821 |
0.35/0.98 |
0.55/0.96 |
0.68/0.94 |
0.77/0.91 |
0.83/0.87 |
| 17.50 |
0.855 |
0.821 |
0.35/0.98 |
0.54/0.96 |
0.67/0.93 |
0.76/0.89 |
0.83/0.85 |
| 18.50 |
0.819 |
0.836 |
0.36/0.98 |
0.56/0.95 |
0.68/0.92 |
0.77/0.87 |
0.83/0.82 |
| 19.50 | 0.782 | 0.843 | 0.36/0.97 | 0.55/0.94 | 068/0.90 | 0.77/0.85 | 0.83/0.79 |
Note: *indicates the cutoff with optimal sensitivity and specificity.