. 2019 Jul 25;16:21. doi: 10.1186/s12987-019-0142-9

Table 2.

Comparison of clinical characteristics and outcomes in 175 probable iNPH patients using different prognostic tests

Variables	Tap positive, infusion test not performed n = 98			Tap negative, infusion test not performed n = 29			Tap negative, infusion test positive n = 34			Tap negative, infusion test negative n = 14			Test statistics (df)	Test of strength	p value
Variables	Number of participants	%	Number of observations if any missing data	Number of participants	%	Number of observations if any missing data	Number of participants	%	Number of observations if any missing data	Number of participants	%	Number of observations if any missing data	Test statistics (df)	Test of strength	p value
Outcome
Favorable clinical outcome 3 months postoperatively (yes)	83	85		26	93	28	28	82		11	79		2.23 (3)		0.527^a
Walking speed improvement 3 months postoperatively (yes)	55	75	73	14	58	24	12	41	29	4	36	11	10.72 (3)	0.32^c	0.003 ^b
Favorable INPHGS outcome 3 months postoperatively (yes)	41	48	86	10	43	23	11	36	31	7	70	10	3.86 (3)		0.278^b
Favorable HRQoL outcome 3 months postoperatively (yes)	31	52	59	7	54	13	14	67	21	3	43	7	1.75 (3)		0.626^a
Characteristics
Age (at referral to the neurosurgical department)	74.3^f	6.9^g		73.5^f	6.1^g		74.1^f	7.3^g		72.4^f	9.2^g		0.66		0.882^d
Sex (female)	43	44		13	45		18	53		8	64		2.58 (3)		0.460^b
INPH related symptoms
Impairment of gait	98	100		28	97		32	94		13	93		7.02 (3)		0.071^a
Urinary incontinence or urge	80	82		23	79		26	76		14	100		3.87 (3)		0.276^a
Impaired cognition	79	81		27	93		28	82		13	93		4.04 (3)		0.257^b
Full triad	65	66		21	72		21	62		12	86		3.01 (3)		0.390^b
Onset of iNPH related symtoms													4.05 (3)		0.256^b
Onset a year or less from the referral	35	36	95	7	24		15	46	33	7	50
Onset more than a year from the referral	60	64	95	22	76		18	54	33	7	50
First symptom of iNPH
Impairment of gait or imbalance	54	55		17	59		9	27		7	50		9.41 (3)	0.23^c	0.024^b
Cognition impairment	21	21		6	21		11	32		6	43		4.03 (3)		0.258^a
Vertigo	10	10		0	0		7	21		1	7		9.59 (3)	0.21^c	0.022^a
Urinary incontinence or urge	8	8		3	10		3	9		0	0		2.57 (3)		0.463^a
Other	5	5		3	10		3	9		0	0		3.09 (3)		0.379^a
Severity of INPH related symptoms preoperatively
INPHGS total score (0–12)	6.1^f	2.6^g	94	5.9^f	2.8^g		5.6^f	2.8^g		6.7^f	2.6^g	13	1.80		0.614^d
Cognition impairment (MMSE score, 0–30)	22.0^f	4.9^g		22.9^f	4.2^g		22.5^f	4.5^g		23.1^f	3.1^g	13	0.73		0.865^d
Comorbidity
Presence of Aβ or HPτ found in the frontal cortical biopsy	56	60	93	9	34	26	17	55	31	5	45	11	5.71 (3)		0.126^b
Surgical complications	9^h	9		5ⁱ	17		1^j	3		1^k	7				0.259^a

iNPH Idiopathic normal pressure hydrocephalus, iNPHGS iNPH Grading Scale, MMSE Mini-Mental State Examination, Aβ amyloid-beta, HPτ hyperphosphorylated tau

Statistically significant difference (Bonferroni correction, p < 0.0025) is italic

^aMaximum likelyhoodratio Chi square test

^bPearson Chi square test

^cCramer’s V

^dIntependent-Samples Kruskal–Wallis Test

^fmean value

^gstandard deviation

^h2 acute subdural hematomas caused by post-operative falling, 2 chronic subdural hematomas, 1 ventricular catheter displacement, 2 shunt infections, 1 peritoneal catheter displacement, 1 intracerebral hemorrhage

ⁱ3 chronic subdural hematoma, 2 shunt infections

^j1 peritoneal catheter displacement

^k1 peritoneal catheter displacement. Strength statistics were reported only for the statistically significant group differences