Table 5 –

Discrimination analysis of the single-time randomly selected 22-item version of the Northwestern Anagram Test-Italian for the classification of nfvPPA and lvPPA cases. Items were sorted from the highest to the lowest relative variable importance (RVIMP) calculated by the Random Forest algorithm.

	RVIMP	AUC	AUC 95% lower	AUC 95% upper	Threshold	Accuracy	Sensitivity	Specificity
NAT-I, total score	100.00%	.94	.83	1	16.75	90.50%	87.50%	92.30%
Non-canonical, score	62.77%	.92	.81	1	5.75	85.70%	87.50%	84.60%
Complex active, score	40.51%	.87	.70	1	6.50	85.70%	87.50%	84.60%
Passive, score	22.79%	.87	.72	1	3.25	81.00%	87.50%	76.90%
Canonical, score	22.32%	.86	.68	1	8.50	81.00%	87.50%	76.90%
Questions, score	18.47%	.88	.74	1	2.75	81.00%	87.50%	76.90%
Simple active, time	1.07%	.61	.30	.92	45.43	76.20%	50.00%	92.30%
Complex active, time	.11%	.76	.53	.99	499.49	76.20%	75.00%	76.90%
NAT-I, total time	−.02%	.72	.47	.97	1252.72	71.40%	87.50%	61.50%
Simple active, score	−.43%	.71	.52	.91	3.50	66.70%	75.00%	61.50%
Passive, time	−.46%	.70	.45	.95	107.00	76.20%	50.00%	92.30%
Canonical, time	−1.50%	.71	.46	.97	546.00	76.20%	62.50%	84.60%
Non-canonical, time	−3.85%	.67	.42	.93	489.50	66.70%	87.50%	53.80%
Questions, time	−4.21%	.65	.38	.92	259.78	66.70%	87.50%	53.80%

‘Time’ is reported in terms of seconds. Abbreviations: AUC = area under the ROC curve; nfvPPA = nonfluent variant of primary progressive aphasia; RIVMP = relative variable importance [i.e., variable importance (VIMP)/max VIMP × 100]; NAT-I = Northwestern Anagram Test-Italian.

Accuracy, sensitivity and specificity were calculated at the optimal threshold of the ROC curve, which jointly maximizes sensitivity and specificity.