Table 2 Asthma diagnosis and asthma symptoms in relation to traffic.

n

n (%)

OR ^a

n

n (%)

OR ^a,

Heavy traffic

No

6041

400(6.6%)

1.00

6041

668(11.1%)

1.00

Yes

3275

286(8.7%)

1.28(1.09–1.50)

3275

447(13.6%)

1.22(1.07–1.39)

Heaviest road within <100 m

no heavy road

3755

269(7.2%)

1.00

3755

419(11.2%)

1.00

<2 cars/min

2235

149(6.7%)

0.92(0.75–1.13)

2235

263(11.8%)

1.05(0.89–1.24)

2–5 cars/min

1820

134(7.4%)

1.00(0.81–1.25)

1820

216(11.9%)

1.06(0.89–1.26)

6–10 cars/min

886

69(7.8%)

1.05(0.79–1.38)

886

126(14.2%)

1.25(1.01–1.55)

>10 cars/min

578

61(10.6%)

1.40(1.04–1.89)

578

85(14.7%)

1.29(1.00–1.67)

NO_x (μg/m³)

0–8

1855

140(7.5%)

1.00

1855

217(11.7%)

1.00

8–11

1855

146(7.9%)

1.04(0.82–1.32)

1855

213(11.5%)

0.97(0.80–1.19)

11–14

1855

124(6.7%)

0.85(0.66–1.09)

1855

208(11.2%)

0.94(0.77–1.15)

14–19

1858

115(6.2%)

0.77(0.60–1.00)

1858

206(11.1%)

0.90(0.74–1.11)

>19

1851

157(8.5%)

1.05(0.83–1.34)

1851

265(14.3%)

1.21(0.99–1.46)

p-trend

0.84

p-trend

0.026