Evaluating the cerebrospinal fluid tap test with the Hellström iNPH scale for patients with idiopathic normal pressure hydrocephalus

Table 3 Sensitivity, specificity, PPV, NPP and accuracy

	Gait domain CSF TT/total iNPH scale postoperatively^a N = 116	Balance domain CSF TT/Total iNPH scale postoperatively^a N = 115	Gait and Balance domain CSF TT/total iNPH scale postoperatively^a N = 116	Gait domain CSF TT/GAIT domain postoperatively^b N = 116
Sensitivity	68.1	47.8	29.7	71.8
Specificity	52.0	68.0	76.0	51.6
Positive predictive value	83.8	84.3	81.8	82.4
Negative predictive value	31.0	26.6	23.0	42.9
Accuracy	64.7	52.2	40.0	68.1

Sensitivity, specificity, positive predictive value, negative predictive value and accuracy for the CSF TT with cut off ≥ 5 points in the gait domain or ≥ 16 points in the balance domain or in a combination of both on the iNPH scale
^aPositive outcome after surgery ≥ 5 points on the total iNPH scale
^bPositive outcome after surgery ≥ 5 points in the gait domain

ISSN: 2045-8118