Table 1—

Characteristics of asthmatic subjects and controls

CharacteristicAsthmatic subjectsAsymptomatic controlsBronchitis controls
Subjects n244517
Age yr46±9 (37–70)46±11 (27–80)46±11 (34–70)
Sex male16 (67)16 (67)9 (53)
Smoking
 Never6 (25)25 (55.6)6 (35.3)
 Past9 (37.5)16 (35.6)8 (47.1)
 Current9 (37.5)4 (8.9)3 (17.6)
Prebronchodilator FEV1 % pred69.2±13.9102.0±8.5103.7±12.4
  • Data presented as mean±sd or n (%)

  • Due to some missing data average number of packs per year or time since stopping smoking could not be calculated for smoking groups

  • FEV1: forced expiratory volume in one second