Table 2

Change in pulmonary function tests (% predicted) over first day

	A	n	P	n	Difference A − P	95% CI for difference	p value
Forced expiratory volume in one minute (FEV₁)
6 h	14.1	25	3.7	17	10.4	(4.2 to 16.6)	0.0016
12–18 h	17.1	19	7.6	16	9.5	(2.6 to 16.3)	0.0082
24 h	22.5	22	13.1	17	9.4	(1.0 to 17.9)	0.029

Maximum mid-expiratory volume (MMEF)
6 h	13.3	25	−0.4	17	9.3	(4.3 to 15.7)	0.0016
12–18 h	13.2	19	6.9	16	6.3	(0.3 to 12.3)	0.041
24 h	17.1	22	11.6	17	5.5	(−3.0 to 14.1)	0.2

Peak expiratory flow rate (PEFR)
6 h	14.8	25	−0.3	17	15.1	(6.5 to 23.7)	0.001
12–18 h	16.6	19	6.3	16	10.3	(1.7 to 18.9)	0.02
24 h	22.4	22	12.2	17	10.2	(0.3 to 19.9)	0.043

Group means for FEV₁ and PEFR are compared using at test.
For change in MMEF as percentage predicted over first three days, group medians are compared using a Mann-Whitney test, and the difference (A − P) is the point estimate for the difference between medians.
A; aminophylline, P; placebo, n; number of subjects.