Dose omission to shorten methacholine challenge testing: clinical consequences of the use of a 10% fall in FEV1 threshold

Table 2 Patient characteristics according to the presence of adverse events

	Adverse event	No adverse event	p
n	11	197
Age	55 (14)	52 (15)	0.49
Male sex	7 (64)	128 (65)	0.93
BMI	28.3 (4.4)	28.0 (6.1)	0.87
History of asthma	5 (45)	55 (28)	0.14
Atopy	5 (45)	105 (55)	0.74
Use of any inhaled medication	8 (80)	93 (48)	0.05
Lung function testing^a
FEV₁/FVC	0.71 (0.41)	0.79 (0.35)	0.02
FEV₁, %	84 (14)	96 (14)	0.005
FVC, %	80 (29)	96 (13)	0.001
RV, %	141 (53)	98 (20)	< 0.001
FRC, %	116 (28)	95 (17)	< 0.001
TLC, %	110 (16)	102 (12)	0.06
D_LCO, %	92 (33)	95 (19)	0.66
Methacholine challenge
Starting dose, mg/ml	1 (0.25–1)	1 (0.25–1)	0.46
PC₂₀, mg/ml^b	2.4 (1.7)	5.5 (4.4)	0.03
Dose skipped after FEV₁ decreased 5–10%	4 (36)	86 (44)	0.64
Dose skipped after FEV₁ decreased 5–10% and PC₂₀ reached	3 (27)	16 (8)	0.03
Number of skipped doses after FEV₁ decreased 5–10%	0 (0–1)	0 (0–1)	0.40

Data presented as mean (standard deviation), median (interquartile range) or n (percent), where appropriate
FEV₁ forced expiratory volume in 1 s, FVC forced vital capacity, RV residual volume, FRC functional residual capacity, TLC total lung capacity, DLCO diffusion capacity of the lung for carbon monoxide
^aData available for X patients
^bData available for the 77 patients with PC₂₀ < 16 mg/ml

ISSN: 1710-1492