Table 3 Mean differences in clinical and lung function parameters in the fluticasone/salmeterol (FP/S) group compared with the fluticasone (FP) group over the 1 year treatment period.

	Mean difference FP/S − FP	p value
PEF morning (l/min)*	29 (9)	<0.001
PEF evening (l/min)*	36 (9)	<0.001
Symptom score morning (scale 0–4)*	−0.1 (0.1)	0.02
Symptom score evening (scale 0–5)*	−0.2 (0.1)	0.01
Short acting β2 agonist usage (puffs/day)*	−0.9 (0.3)	<0.001
FEV1 (% predicted)*	2.7 (1.5)	0.07
PC20histamine (doubling doses)†	0.7 (0.3)	0.02

Values are expressed as *mean or †geometric mean (SE).

PEF, peak expiratory flow; FEV₁, forced expiratory volume in 1 second; PC₂₀histamine, concentration of histamine provoking a fall in FEV₁ of at least 20%.