Table 1. Demographic data of participants, their lung function and methacholine challenge test results (n = 46).

Demographic variable	Mean (range) or n (%) or Mean ± SD
Age, years	60.5 (25–82)
Race, non-white	28 (60.9%)
Atopy	16 (36.8%)
Years from initial diagnosis	24.9±7.2
Years from last exposure	14.8±10.3
Asthma score	2.9 (0–11)
Impairment class:
Class 0	2 (4.3%)
Class 1	23 (50.0%)
Class 2	21 (45.7%)
Inhaled steroid	19 (41.3%)
FEV1 (% predicted)	76.18±16.15
FEV1/FVC	0.72±0.07
PC20 (mg/ml)	6.34±6.55
BRI	1.26±0.14