Table 3.

Receiver operating characteristic curve statistics and cutoff thresholds for the TWT (raw scores, motor DTEs) to discriminate younger adults (Y), healthy older adults (HC), and older adults with probable MCI (pMCI).

Variables	Group	n	Youden index	Sensitivity	Specificity	Score threshold	AUC	p
TWT-1	Y vs. HC	42/24	0.74	95.8	78.6	25.31	0.941	< 0.001
	Y vs. pMCI	42/19	0.76	94.8	81.0	25.63	0.955	< 0.001
	HC vs. pMCI	24/19	0.22	47.4	75.0	33.71	0.612	0.211
TWT-2	Y vs. HC	42/24	0.86	100.0	85.7	36.09	0.975	< 0.001
	Y vs. pMCI	42/19	0.88	94.7	92.9	37.62	0.985	< 0.001
	HC vs. pMCI	24/19	0.44	52.6	91.7	52.63	0.704	0.020
TWT-3	Y vs. HC	42/24	0.83	100.0	83.3	41.29	0.953	< 0.001
	Y vs. pMCI	42/19	0.99	100.0	99.9	54.69	0.999	< 0.001
	HC vs. pMCI	24/19	0.67	100.0	66.67	57.18	0.860	< 0.001
DTEm TWT-2 – MS	Y vs. HC	37/24	0.41	70.8	70.3	−36.90	0.678	0.019
	Y vs. pMCI	37/19	0.49	79.0	70.3	−37.00	0.755	< 0.001
	HC vs. pMCI	24/19	0.31	47.0	83.3	−50.14	0.625	0.165
DTEm TWT-3 - MS	Y vs. HC	41/24	0.34	75.0	58.5	−59.96	0.646	0.043
	Y vs. pMCI	41/19	0.68	89.5	78.1	−73.70	0.890	< 0.001
	HC vs. pMCI	24/19	0.52	89.5	62.5	−73.70	0.794	< 0.001
DTEc_TWT-2 - MS	Y vs. HC	37/24	0.25	62.5	62.2	−495	0.602	0.183
	Y vs. pMCI	37/19	0.39	52.6	86.5	−283	0.687	0.017
	HC vs. pMCI	24/19	0.28	52.6	75.0	−281	0.596	0.283
DTEc TWT-3 - MS	Y vs. HC	41/24	0.19	33.3	85.4	−60.82	0.564	0.396
	Y vs. pMCI	41/19	0.54	68.4	85.4	−60.82	0.697	0.020
	HC vs. pMCI	24/19	0.43	68.4	75.0	−59.43	0.662	0.079

AUROC, area under the receiver operating characteristic curve; TMT, Trail Making Test; TWT, Trail Walking Test; DTEm, Dual Task effects motor; MS, motor speed. For continuous variables cutoff thresholds were set at the optimum balance between sensitivity and specificity as determined by calculation of the Youden index. The threshold value for dichotomous variables was 1.