Table 3– Summary of studies presenting sensitivity and specificity of their cut-off values for nNO for PCD versus healthy patients

Study	Subjects n	nNO cut-off nL·min⁻¹	Sensitivity %	Specificity %
*Mateos-Corral et al.* [26], 2011^#**	44	60.8	100	100
*Narang et al.* [7], 2002**	157	25	75	96
		62.5	97	90
*Horvath et al.* [8], 2003**	102	46.8	93	95
*Corbelli et al.* [10], 2004**	34	126	94	88
Marthin and Nielsen [25], 2011	94	Breath hold 52.5	91.1	100
		Oral exhalation 72.6	94.3	100
		Tidal breathing 47.4	94.4	100
*Leigh et al.* [19], 2013**	227	77	98	>99.9
Marthin and Nielsen [17], 2013	57	78.6	100	100
*Harris et al.* [32], 2014**	47	38	100	95
*Boon et al.* [31], 2014**	226	90	89.5	87.3

nNO: nasal nitric oxide; PCD: primary ciliary dyskinesia. ^#: bronchiectasis patients included in healthy control group.