Table 1– Summary of studies measuring nNO in PCD, healthy control and cystic fibrosis groups using a stationary analyser with a velum closure manoeuvre

	PCD		Healthy controls		Cystic fibrosis
	Subjects n	Mean±sd nL·min⁻¹	Subjects n	Mean±sd nL·min⁻¹	Subjects n	Mean±sd nL·min⁻¹
Study
Wodehouse et al. [9], 2003	42	16.4±9.2	16	189.8±36.5	15	139.5±40.7
Csoma et al. [20], 2003	15	14.9±11.8	14	126.4±62.5
Noone et al. [21], 2004	64	19±17	27	376±124	11	184±109
Corbelli et al. [10], 2004	17	16.4±4.35	24	268.4±138.5
Piacentini et al. [22], 2008	10	8.9±5.7	26^¶	195±92.8
Shoemark et al. [23], 2009	20	12.3±8.6	20	159.8±133.5
Moreno Galdó et al. [24], 2010	9	22±29.9	37	224.5±37.1	210	109.5±27
Marthin and Nielsen [25], 2011	45	19.0±13.6	57	272.4±76.0	49	124.8±103.7
Mateos-Corral et al. [26], 2011	20	17.9±13.7	19	366.5±131.7	32	138.8±84.1
Leigh et al. [19], 2013	149	20.7±24.1	78	304.6±118.8	77	134.0±73.5
Leigh et al. [19], 2013^#	71	23.3±18.0
Marthin and Nielsen [17], 2013	16	23.7±22.8	20	267±74.4	21	150.3±58.8
Combined	478	19.4±18.6	338	265.0±118.9	415	123.2±62.7
ppb equivalents⁺
NIOX (Flex/MINO)^§		64.7		883.3		410.7
Eco Medics CLD 88^ƒ		58.8		803.0		373.3
Sievers^##		38.8		530.0		246.4
LR2000^¶¶		77.6		1060.0		492.8

nNO: nasal nitric oxide; PCD: primary ciliary dyskinesia. ^#: replication; ^¶: results from co-operative healthy controls only; ⁺: calculated by using mean in nL·min⁻¹/machine sampling rate; ^§: Aerocrine AB, Solna, Sweden; ^ƒ: Eco Medics AG, Duernten, Switzerland; ^##: GE Analytical Instruments, Boulder, CO, USA; ^¶¶: Logan System, Rochester, UK.