Table 4.

Mean percent predicted spirometry values stratified by primary diagnosis.

	Mean percent predicted [interquartile range]
	FVC	FEV1	FEF25–75%	FEV1/FVCa
Asthma (n = 56)	89 [77–103]	96 [86–110]	96 [71–116]	102 [98–107]
Cystic fibrosis (n = 9)	94 [84–100]	98 [85–108]	99 [76–116]	99 [95–106]
Total (n = 135)	89 [77–101]	95b [84–107]	96c [73–114]	100 [96–106]

Note. FVC = forced vital capacity; FEV₁ = forced expiratory volume in one second; FEF_25–75% = forced expiratory flow between 25% and 75% of FVC.

^aFEV₁/FVC was calculated as a ratio and transformed to a percentage.

^b133 children produced an FEV₁.

^c104 children produced a value for FEF_25–75%.