Table 3 Comparison of ARI cases with matched hospital controls: analysis of vaccination status, underlying illness and other potential risk factors

Pandemic influenza vaccination

150

7

246

7

1.0 (0.4-2.5)

0.94

Seasonal influenza vaccination 2009/10

150

31

237

22

1.7 (1.1-2.8)

0.03

Seasonal influenza vaccination 2008/09

144

22

239

24

0.8 (0.4-1.5)

0.51

Seasonal influenza vaccination 2007/08

142

19

239

22

0.6 (0.4-1.7)

0.63

Pneumococcal vaccine

131

15

211

5

4.3 (1.5-11.8)

0.005

Pandemic influenza vaccine offered by employer

148

10

245

20

0.4 (0.2-0.8)

0.01

Any chronic underlying illness

152

67

246

57

4.5 (1.9-10.4

0.001

Any chronic lung disease

151

26

246

6

12.9 (4.5-36.4)

<0.0001

COPD

150

16

246

10

1.9 (1.0-3.6)

0.05

Asthma

151

16

246

10

2.1 (1.0-4.3)

0.05

Chronic bronchitis

152

35

244

18

3.4 (1.9-6.1)

<0.0001

Cardiovascular disease

152

39

245

30

1.9 (1.1-3.2)

0.02

Immunosuppression

146

15

246

0.4

35.2 (4.7-262.5)

0.001

BMI ≥31

151

21

244

24

0.9 (0.5-1.4)

0.54

Frailty

151

9

246

6

1.8 (0.8-4.0)

0.18

≥ 3 physician visits in past year

151

55

242

53

1.0 (0.7-1.6)

0.88

≥ 1 hospitalization in past year

152

30

245

34

0.9 (0.5-1.4)

0.57

Current smoker

152

44

246

47

0.9 (0.6-1.3)

0.53

>20 packyears vs. non-smoker

152

32

246

31

1.3 (0.7-2.3)

0.41

Alcohol: ≥ 1 drink/week

150

55

234

63

0.7 (0.4-1.0)

0.07

Children in household

152

38

246

19

2.7 (1.6-4.3)

<0.0001

Public transport (> = 3x/week) vs. none

152

41

244

44

0.9 (0.6-1.4)

0.52

Owns car

152

53

243

60

0.8 (0.5-1.1)

0.18

Completion of at least Grade 10

149

66

239

77

0.6 (0.4-0.9)

0.02

Private health insurance

152

15

244

19

0.6 (0.3-1.1)

0.11