Table 2.

Characteristics of the Patients in Which Proximal Bronchi Biopsy Samples Were Obtained

	Mean ± SD	Median	Range
Age, years	56.3 ± 8.9	60	42–46
Actual smoking, cigarettes/day	15.4 ± 7.4	13	6–30
Pack-years	25.3 ± 11.2	21	5–50
FEV1, % predicted	62.5 ± 12.9	65	34–93
Reversibility, % predicted	5.3 ± 3.1	5	0–9.0
PC20, mg/ml
For histamine	1.7 ± 2.1	0.87	0.11–8
For methacholine	4.6 ± 5.5	1.72	0.6–17.4

Abbreviations: FEV¹, forced expiratory volume in 1 second; SD, standard deviation; PC₂₀, provocative concentration causing a 20% fall in FEV₁.