Table 3.
Diagnostic parameters for the MoCA and short form MoCA in the full sample, AD, MCI, PD and PDD
| Full sample vs HC | AD vs HC | MCI vs HC | PD vs HC | PDD vs PD | ||
|---|---|---|---|---|---|---|
| MoCA | AUC (±95% CI*) | 0.83 (0.81 to 0.86) | 0.99 (0.99 to 1.00) | 0.94 (0.91 to 0.96) | 0.72 (0.68 to 0.75) | 0.69 (0.65 to 0.77) |
| Sensitivity/specificity | 0.57/0.97 | 0.95/1.00 | 0.91/0.80 | 0.52/0.80 | 0.69/0.64 | |
| Youden index | 0.56 | 0.94 | 0.71 | 0.32 | 0.33 | |
| Cut-off score | 24 | 23 | 26 | 26 | 24 | |
| PPV/NPV | 0.99/0.21 | 1.00/0.90 | 0.75/0.93 | 0.92/0.28 | 0.94/0.21 | |
| Classification accuracy | 61% | 96% | 84% | 58% | 68% | |
| Short form MoCA | AUC (±95% CI) | 0.79 (0.76 to 0.82)† | 0.99 (0.99 to 1.00) | 0.92 (0.89 to 0.95) | 0.67 (0.63 to 0.70)† | 0.71 (0.66 to 0.77) |
| Sensitivity/specificity | 0.62/0.86 | 0.96/0.93 | 0.84/0.86 | 0.40/0.86 | 0.63/0.69 | |
| Youden index | 0.51 | 0.89 | 0.70 | 0.28 | 0.32 | |
| Cut-off score | 12 | 11 | 12 | 12 | 12 | |
| PPV/NPV | 0.98/0.20 | 0.97/0.92 | 0.80/0.89 | 0.92/0.25 | 0.94/0.20 | |
| Classification accuracy | 64% | 95% | 85% | 48% | 64% | |
| Horton et al short form MoCA‡ | AUC (±95% CI) | 0.75 (0.72 to 0.78)†§ | 0.99 (0.98 to 0.99) | 0.90 (0.86 to 0.94)† | 0.39 (0.35 to 0.43)†§ | 0.71 (0.65 to 0.76) |
| Sensitivity/specificity | 0.52/0.93 | 0.93/0.97 | 0.73/0.93 | –¶ | 0.54/0.78 | |
| Youden index | 0.45 | 0.90 | 0.66 | –¶ | 0.32 | |
| Cut-off score | 10 | 9 | 10 | –¶ | 11 | |
| PPV/NPV | 0.99/0.17 | 0.99/0.87 | 0.87/0.84 | –¶ | 0.94/0.18 | |
| Classification accuracy | 56% | 95% | 85% | –¶ | 57% | |
All statistics are based on the s-MoCA (eight-item) version.
CIs estimated using DeLong method and n=2000 bootstraps.
Significantly lower than the standard MoCA in permutation testing of AUC using roc.test function in R package pROC (p<0.005).
Eight-item test; score range=0–14.
Significantly lower than the short form MoCA in permutation testing of AUC using roc.test function in R package pROC (p<0.005).
Analysis fails to converge due to poor predictive power (see figure 1D); statistical comparison was estimated for AUC.
AD, Alzheimer’s disease; AUC, area under the curve; HC, healthy control; MCI, mild cognitive impairment; MoCA, Montreal Cognitive Assessment; NPV, negative predictive value; PD, Parkinson’s disease; PDD, PD with dementia; PPV, positive predictive value; s-MoCA, short form MoCA.