Table 3. Positive ratios of TCS, cardiac MIBG scintigraphy and olfactory function tests for the PD vs. PSP and PD vs. MSA groups.

(A) PD vs. PSP
Combinations of test results		PD (n = 101)	PSP (n = 17)	p-value	PD diagnosis
option					Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)
1	SN+ (≥0.16 cm2)	34 (53.1%)	0 (0%)	0.003	53.1	100	100	23.1
	MIBG+ (≤2.0)	71 (70.3%)	2 (11.8%)	<0.001	70.3	88.2	97.3	33.3
	OE+ (≤4)	59 (58.4%)	5 (29.4%)	0.026	58.4	70.6	92.2	22.2
2	At least one positive result from 3 tests	87(86.1%)	7 (41.2%)	<0.001	86.1	58.8	92.6	41.7
3	At least two positive results from 3 tests	60 (59.4%)	0 (0%)	<0.001	59.4	100	100	29.3
	(SN or MIBG) and OE	52(51.5%)	0(0%)	<0.001	51.5	100	100	25.8
	(OE or MIBG) and SN	29(45.3%)	0(0%)	0.009	45.3	100	100	20.5
	(OE or SN) and MIBG	56(55.4%)	0(0%)	<0.001	55.4	100	100	27.4
4	Positive results for all 3 tests	17(26.6%)	0(0%)	0.078	26.6	100	100	16.1
(B) PD vs. MSA
Combinations of test results		PD (n = 101)	MSA (n = 21)	p-value	PD diagnosis
option					Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)
1	SN+ (≥0.16 cm2)	34 (53.1%)	2 (13.3%)	0.005	53.1	86.7	94.4	30.2
	MIBG+ (≤2.0)	71 (70.3%)	3 (14.3%)	<0.001	70.3	85.7	95.9	37.5
	OE+ (≤4)	59 (58.4%)	4 (19%)	0.001	58.4	81.0	93.7	28.8
2	At least one positive result from 3 tests	87(86.1%)	7(33.3%)	<0.001	86.1	66.7	92.6	50
3	At least two positive results from 3 tests	60(59.4%)	2(9.5%)	<0.001	59.4	90.5	96.8	31.7
	(SN or MIBG) and OE	52(51.5%)	1(4.8%)	<0.001	51.5	95.2	98.1	29.0
	(OE or MIBG) and SN	29(45.3)	1(6.7%)	0.006	45.3	93.3	96.7	28.6
	(OE or SN) and MIBG	56(55.4%)	2(9.5%)	<0.001	55.4	90.5	96.6	29.7
4	Positive results for all 3 tests	17(26.6%)	0(0%)	0.024	26.6	100	100	24.2

SN+ = substantia nigra hyperechogenicity positive; MIBG+ = cardiac MIBG scintigraphy positive; OE+ = olfactory testing positive; PPV = positive predictive value; NPV = negative predictive value.