The Reliability of a Novel Structured Testing Device for Single-breath Lung Carbon Monoxide Uptake: A Randomized Comparison Crossover Study

Table 1 Intrasession variability characteristics and compliance rates for the F_ICO and F_ICH4 of Masterscreen and MeAir

Gas	Variables	MasterScreen	MeAir
F_ICO	Measured value	0.295(0.291,0.299)	0.298(0.296,0.300)
	Min-Max	0.262–0.310	0.287–0.305
	CV	2.6%	1.2%
	Measurement error	-12.667%∼1.667%	-4.333%∼1.667%
	The proportion of acceptable	57/160(35.63%)	101/160(63.13%)
F_ICH4	Measured value	0.301(0.297,0.305)	0.299(0.295,0.301)
	Min-Max	0.266–0.314	0.287–0.304
	CV	3.0%	1.2%
	Measurement error	-11.333%∼4.667%	-4.333%∼1.333%
	The proportion of acceptable	69/160(43.13%)	107/160(66.88%)

The target gas concentration is 0.3%. As the data distribution of inhaled gas (both the two devices) do not conform to the normal distribution, so data are presented as median (P25,P75) and minimum to maximum. F_ICO (%): fractional concentration of Inspired carbon monoxide; F_ICH4 (%): fractional concentration of Inspired methane; CV: coefficient of variation; The measurement error is calculated by the difference between the minimum gas concentration and maximum gas concentration to the target gas concentration as a percentage of the target gas concentration. The proportion of acceptable is the ratio where the measurement error is within 1%

ISSN: 1471-2466