Clinimetrics of the 9- and 19-Item Wearing-Off Questionnaire: A Systematic Review

Table 2

WOQ-9.

Author	Year	N	Cut-off	Sn	Sp	PPV	NPV
Stacy et al. [6]	2008	216	1	0.96	0.40	0.48	0.94
Chan et al. [14]	2011	101	1	0.87	0.69	0.86	0.71
Bares et al. [15]	2012	563	1	0.98	0.27	0.72	0.91
Santos et al. [16]	2014	60	1	1	0.10	0.54	1
Fukae et al. [17]	2015	180	1	0.94	0.39	0.66	0.83

Sn: sensitivity; Sp: specificity; PPV: positive predictive value; NPV: negative predictive value.