Table 1

Association between asthma and risk factors included in analyses

Risk factor No. (%) of cases (total 664) No. (%) of controls (total 910) Crude OR (95% CI)
Sex
 Female412  (62)538  (59)1
 Male252 (38)372 (41)0.88 (0.72 to 1.09)
Age group
 15–1965 (10)55 (6)1
 20–2486 (13)72 (8)1.01 (0.63 to 1.63)
 25–2988 (13)104 (11)0.72 (0.45 to 1.13)
 30–3498 (15)153 (17)0.54 (0.35 to 0.84)
 35–39107 (16)181 (20)0.50 (0.32 to 0.77)
 40–44100 (15)143 (16)0.59 (0.38 to 0.92)
 45–51120 (18)202 (22)0.50 (0.33 to 0.77)
Social class
 I34 (5)92 (10)0.44 (0.29 to 0.69)
 II202 (30)327 (36)0.74 (0.57 to 0.96)
 IIINM201 (30)241 (27)1
 IIIM117 (18)146 (16)0.96 (0.71 to 1.31)
 IV/V110 (17)104 (11)1.27 (0.91 to 1.76)
Type of accommodation
 Owned377 (57)635 (70)1
 Rented287 (43)275 (30)1.76 (1.43 to 2.17)
Unemployed
 No465 (70)715 (79)1
 Yes179 (27)174 (19)1.58 (1.25 to 2.01)
 Not stated20 (3)21 (2)1.46 (0.79 to 2.73)
Single parent
 No567 (85)831 (91)1
 Yes97 (15)79 (9)1.80 (1.31 to 2.47)
Smoking
 Never306 (46)445 (49)1
 Ex124 (19)169 (19)1.07 (0.81 to 1.40)
 Current234 (35)296 (33)1.15 (0.92 to 1.44)
Passive smoking in household
 No411 (62)641 (70)1
 Yes253 (38)269 (30)1.47 (1.19 to 1.81)