Table 2 Clinical characteristics of laboratory-confirmed influenza A and B cases (1993–2008)

Asthma

141

10.0

51

11.5

0.393

Any cardiovascular disease

585

41.7

110

24.7

<.001

Chronic obstructive pulmonary disease

242

17.2

45

10.1

<.001

Diabetes

133

9.5

20

4.5

<.001

Immunosuppressed

252

17.9

61

13.7

0.038

Any chronic disease*

625

44.5

145

32.6

<.001

Mean Charlson index (SD)

1

1.3

0

0.9

<.001

Any hospital admissions in last 5 years

1,046

74.5

252

56.6

<.001

Median hospital admission in last 5 years (IQR)

2

0 - 3

1

0 - 2

<.001

Had ≥37 physician visits in last 5 years

703

50.1

154

34.6

<.001

Median physician visit in last 5 years (IQR)

37

0 - 73

0

0 - 47

<.001

Received the seasonal influenza vaccine

242

17.2

64

14.4

0.158

Timing of receipt of the seasonal influenza vaccine

0.100

  1-13 days before index date

10

0.7

0

0.0

  ≥14 days before the index date

232

16.5

64

14.4

Recommended receipt of the seasonal influenza vaccine

<.001

  Not recommended

305

21.7

187

42.0

  Recommended and received

218

15.5

54

12.1

  Recommended but not received

881

62.7

204

45.8

Received a pneumococcal vaccine

508

36.2

112

25.2

<.001