Table 1.

Group characteristics and lung function of 145 children excluded from analysis by criteria 1 and 2.

	Congenital abnormality*	Sickle cell disease	Current asthma	Total
Subjects (n)	9	12	124	145
Boys (%)	78%	17%	56%	54%
White (%)	56%	17%	32%	32%
Test occasions# (n)	8	18	192	218
Age at test (y)	8.6 (1.88)	8.4 (1.83)	8.7 (1.55)	8.7 (1.58)
zHeight§	−0.17 (1.87)	0.51 (1.03)	0.27 (1.29)	0.28 (1.3)
zFEV1	0.19 (2.68)	−0.50 (1.01)	−0.27 (1.04)	−0.27 (1.13)
zFVC	0.27 (2.82)	−0.37 (1.00)	0.22 (0.99)	0.17 (1.10)
zFEV1/FVC	−0.05 (0.90)	−0.29 (1.04)	−0.85 (0.96)	−0.77 (0.98)

Data presented are Mean (SD) unless otherwise specified.

^§according to the British 1990 reference[12].

^*6 children with congenital or neurological abnormalities and 3 with growth abnormalities.

^#Test occasions with technically acceptable spirometry results.