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Table 4 Subject characteristics and risk of admission with influenza

From: Influenza epidemiology and influenza vaccine effectiveness during the 2016–2017 season in the Global Influenza Hospital Surveillance Network (GIHSN)

 

All admissions

Influenza-positive

Crude OR

Heterogeneity by strain (I2)

aOR(*)

N = 10140

N = 2895

     

Characteristic

N

N

%

Value

95% CI

 

Value

95% CI

Age group

 0–1 years

2692

331

12.3

1.00

79.4%

1.00

 2–4 years

1217

311

25.6

2.45

2.06–2.92

75.6%

0.86

0.67–1.09

 5–17 years

827

381

46.1

6.09

5.03–7.38

94.6%

1.59

0.85–2.96

 18–49 years

2100

795

37.9

4.35

3.73–5.06

96.4%

0.65

0.22–1.97

 50–64 years

735

195

26.5

2.58

2.10–3.15

96.6%

0.59

0.25–1.39

 65–74 years

793

228

28.8

2.88

2.37–3.50

95.3%

0.61

0.31–1.22

 75–84 years

903

272

30.1

3.07

2.55–3.71

96.9%

0.50

0.21–1.20

 ≥ 85 years

701

260

37.1

4.21

3.45–5.13

98.4%

0.49

0.19–1.28

Sex

 Male

5105

1339

26,2%

1.00

 

54.0%

1.00

 

 Female

5035

1556

30,9%

1.26

1.15–1.37

46.5%

0.84

0.74–0.95

Smoking habits

 Current smoker

2270

542

23,9%

1.00

 

81.7%

1.00

 

 Past smoker

2006

640

31,9%

1.49

1.30–1.71

88.4%

1.04

0.89–1.22

 Never smoker

5704

1598

28,0%

1.24

1.11–1.39

34.0%

1.09

0.93–1.28

Consultations at the GP (last 3 months)

 No

3283

779

23,7%

1.00

 

95.0%

1.00

 

 Yes

5725

1398

24,4%

1.04

0.94–1.15

92.6%

0.91

0.69–1.18

Occupation / Social class

 Qualified

3810

1255

32,9%

1.00

 

97.1%

1.00

 

  Skilled

1376

355

25,8%

0.71

0.62–0.81

81.9%

0.83

0.72–0.94

  Low or unskilled

3411

591

17,3%

0.43

0.38–0.48

91.5%

0.63

0.50–0.78

Other risk factors

 Comorbidity

3714

1234

33,2%

1.43

1.31–1.56

98.7%

0.90

0.63–1.30

 Cardiovascular disease

2094

796

38,0%

1.74

1.57–1.92

98.7%

1.01

0.72–1.40

 Chronic obstructive pulmonary disease

1008

206

20,4%

0.62

0.52–0.72

92.5%

0.66

0.45–0.98

 Asthma

463

187

40,4%

1.74

1.44–2.11

94.3%

1.31

0.96–1.77

 Immunodeficiency/organ transplant

222

67

30,2%

1.08

0.81–1.45

85.2%

0.57

0.28–1.17

 Diabetes

1049

362

34,5%

1.36

1.19–1.56

98.1%

1.19

1.03–1.37

 Chronic renal impairment

617

208

33,7%

1.29

1.09–1.54

89.2%

1.06

0.89–1.27

 Chronic neuromuscular disease

426

192

45,1%

2.13

1.75–2.59

91.7%

1.08

0.75–1.56

 Active neoplasm

479

168

35,1%

1.37

1.13–1.67

96.8%

0.63

0.42–0.95

 Chronic liver disease

135

38

28,1%

0.98

0.67–1.43

38.8%

1.09

0.79–1.50

 Autoimmune disease

131

35

26,7%

0.91

0.62–1.35

23.8%

1.14

0.84–1.56

 Obesity

1457

374

25,7%

0.92

0.81–1.04

93.3%

0.83

0.69–1.00

 Pregnancy

942

483

51,3%

2.96

2.58–3.40

97.6%

3.02

1.59–5.76

Days from onset of symptoms to swabbing

 0–2 days

3585

1211

33,8%

1.00

 

92.8%

1.00

 

 3–4 days

3573

1052

29,4%

0.82

0.74–0.90

36.9%

1.05

0.99–1.12

 5–7 days

2505

564

22,5%

0.57

0.51–0.64

83.4%

0.82

0.64–1.07

 8–9 days

394

59

15,0%

0.35

0.26–0.46

65.2%

0.60

0.47–0.77

  1. (*)Adjusted Odds Ratios were obtained using the model described in the ‘Methods’ section (pg.6)