Are exhaled nitric oxide measurements using the portable NIOX MINO repeatable?

Respiratory Research

Table 5 Subgroup analyses of the reproducibility of the absolute value of FeNO in the intervention study participants.

	Mean intraparticipant difference in FeNO (ppb) (95% CI) [p-value] *	Standard deviation (SD) of the intra-participant difference in FeNO (ppb)	95% limits of agreement (ppb)
All participants	0.31	7.45	-14.28 to 14.90
(n = 65)	(1.54, 2.15) [0.740]
Males	-0.26	9.39	-18.66 to 18.14
(n = 38)	(-3.35, 2.82) [0.864]
Females	1.11	3.14	-5.05 to 7.27
(n = 27)	(-0.13, 2.35) [0.078]
Youngest participants	-0.09	4.08	-8.09 to 7.91
(n = 22)	(-1.9, 1.72) [0.918]
Oldest participants	1.10	12.07	-22.55 to 24.75
(n = 21)	(-4.40, 6.89) [0.682]
Participants with a low FEV ₁	-1.45	11.19	-23.38 to 20.48
(n = 22)	(-6.42, 3.51) [0.549]
Participants with a high FEV ₁	0.15	3.28	-6.28 to 6.58
(n = 20)	(-1.39, 1.69) [0.840]

A low FEV₁ implies an FEV₁within the lowest tercile for the intervention study participants (less than 83% predicted), whilst a high FEV₁ implies an FEV₁within the highest tercile for the intervention study participants (greater than 95% predicted).
The youngest participants are those within the lowest tercile for age (less than 10 years 7 months), whilst the oldest participants are those within the highest tercile for age (greater than 12 years 8 months).
95% limits of agreement = Mean intra-participant difference in FeNO ± 1.96 (SD)
* For comparison of the mean intra-participant difference in FeNO in each group against zero (one sample t-test).

ISSN: 1465-993X