Table 2 Univariate analysis of the association between occupational and environmental factors and CRS

Clearance-related job

239(2.5)

32(3.9)

1.56(1.07,2.27)

0.020

Health care-related job

489(5.2)

47(5.7)

1.11(0.82,1.51)

0.509

Occupational exposure to dust

542(5.6)

101(12.0)

2.32(1.85,2.91)

0.001

Occupational exposure to poisonous gas

255(2.6)

58(6.9)

2.75(2.05,3.69)

0.001

Any pet at home

1121(13.4)

154(19.8)

1.60(1.32,1.92)

0.001

Any large piece of carpet at home

540(6.5)

92(11.9)

1.95(1.54,2.46)

0.001

Any carpet at workplace

89(1.1)

51(6.6)

6.55(4.60,9.32)

0.001

Method used to cook at home

 Electric or centralized heating

9352(96.1)

814(96.3)

1

0.559

 Coal

149(1.5)

15(1.8)

1.16(0.68,1.97)

 Firewood

234(2.4)

16(1.9)

0.79(0.47,1.31)

Method of keeping warm in winter

 Electric or centralized heating

6380(96.4)

521(94.2)

1

0.003

 Coal

137(2.1)

1313(2.4)

1.16(0.65,2.07)

 Firewood/charcoal

100(1.5)

19(3.4)

2.33(1.41,3.83)

Use of air conditioning in summer

  < 3 days/week

5154(60.7)

439(56.6)

1

0.016*

 3–6 days/week

2137(25.2)

208(26.8)

1.14(0.96,1.36)

 Everyday

1200(14.1)

129(16.6)

1.26(1.03,1.55)

Exposure to mouldy or damp environments

 Never

7111(85.2)

593(76.5)

1

0.001*

 Occasionally

1021(12.2)

137(17.7)

1.61(1.32,1.96)

 Frequently or everyday

219(2.7)

45(5.8)

2.46(1.77,3.43)