Table 1

Characteristics of the current study population, the Finnish Environment and Asthma Study 1997–2000

CharacteristicsAtopic asthma cases
(n=156)
Non-atopic asthma cases
(n=187)
ACOS cases
(n=25)
Controls
(n=932)
Age, median (Q1, Q3)32.5 (25.5, 45.0)48.0 (39.0, 55.0)53.0 (48.0, 60.0)43.0 (34.0, 52.0)
Gender, n (%)
 Male57 (36.5)54 (28.9)17 (68.0)438 (47.0)
 Female99 (63.5)133 (71.1)8 (32.0)494 (53.0)
Education, n (%)*
 No vocational schooling23 (14.7)42 (22.7)10 (40.0)154 (16.6)
 Vocational course17 (10.9)36 (19.5)8 (32.0)104 (11.2)
 Vocational institution57 (36.5)45 (24.3)1 (4.0)271 (29.2)
 College level36 (23.1)43 (23.2)3 (12.0)261 (28.1)
 University or corresponding23 (14.7)19 (10.3)3 (12.0)138 (14.9)
Smoking, n (%)†
 Never79 (50.6)93 (50.3)2 (8.0)485 (52.2)
 Ex-smoker30 (19.2)47 (25.4)7 (28.0)205 (22.0)
 Current smoker47 (30.1)45 (24.3)16 (64.0)240 (25.8)
Pets indoors sometimes, n (%)121 (77.6)125 (66.8)15 (60.0)616 (66.1)
Indoor mould exposure at work or at home, n (%)‡36 (23.1)38 (20.3)6 (24.0)193 (20.7)
Secondhand smoke exposure, n (%)
 Past 12 months exposure§31 (19.9)40 (21.4)8 (32.0)166 (17.8)
 Cumulative lifetime exposure§¶
 No exposure60 (39.7)65 (36.5)12 (52.2)359 (40.3)
 <100 cigarette-years30 (19.9)39 (21.9)3 (13.0)206 (23.2)
 ≥100 cigarette-years61 (40.4)74 (41.6)8 (34.8)325 (36.5)
  • *Education missing for 4 controls and 2 cases of non-atopic asthma.

  • †Smoking missing for 2 controls and 2 cases of non-atopic asthma.

  • ‡Mould exposure missing (answered ’do not know’) for 1 control.

  • §Combined home and workplace exposure.

  • ¶Cumulative lifetime secondhand smoke exposure missing for 42 controls, for 19 cases of non-atopic asthma and for 5 cases of atopic asthma.

  • ACOS, asthma–COPD overlap syndrome.