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Table 4 Subject characteristics and risk of admission with influenza

From: Influenza epidemiology and influenza vaccine effectiveness during the 2014–2015 season: annual report from the Global Influenza Hospital Surveillance Network

 

All admissions

Influenza-positive

Crude OR

Heterogeneity by strain (I2)a

aORb

 

N = 9164

N = 2177

Characteristic

n

n

%

Value

95 % CI

Value

95 % CI

Age

 0–1 y

1515

144

9.5

1.00

-

32.5 %

1.00

-

 2–4 y

2206

429

19.4

2.30

1.88-2.81

0.0 %

2.14

1.74-2.64

 5–17 y

827

280

33.9

4.87

3.90-6.10

73.3 %

4.34

3.42-5.51

 18–49 y

1461

423

29.0

3.88

3.16-4.77

59.2 %

3.11

2.49-3.90

 50–64 y

748

191

25.5

3.26

2.57-4.14

72.5 %

4.08

3.11-5.36

 65–74 y

819

211

25.8

3.30

2.62-4.17

67.8 %

4.99

3.76-6.64

 75–84 y

1227

294

24.0

3.00

2.42-3.72

62.4 %

4.51

3.43-5.92

 ≥85

811

205

25.3

3.22

2.55-4.07

71.2 %

4.79

3.59-6.40

Sexc

 Male

5417

1141

21.1

1.00

-

0.0 %

1.00

-

 Female

4197

1036

24.7

1.24

1.13-1.37

0.0 %

1.21

1.09-1.34

 Female non-pregnant

3899

876

22.5

1.11

1.00-1.22

0.0 %

1.10

0.99-1.23

Other risk factors (excludes pregnant women)

 Comorbidityd

3709

856

23.1

1.15

1.04-1.27

62.8 %

1.48

1.30-1.69

 Cardiovascular disease

1996

468

23.4

1.17

1.04-1.33

22.2 %

1.47

1.25-1.72

 Chronic obstructive pulmonary disease

1458

306

21.0

1.02

0.88-1.17

57.6 %

1.39

1.15-1.68

 Asthma

440

96

21.8

1.07

0.84-1.35

0.0 %

1.37

1.04-1.80

 Immunosuppression

106

14

13.2

0.58

0.33-1.03

0.0 %

0.76

0.40-1.46

 Diabetes

1048

234

22.3

1.10

0.94-1.29

0.0 %

1.36

1.10-1.70

 Renal disease

588

129

21.9

1.08

0.88-1.32

48.2 %

1.23

0.95-1.59

 Neuromuscular

167

52

31.1

0.93

0.68-1.26

38.9 %

1.13

0.80-1.58

 Neoplasm (active)

301

63

20.9

1.01

0.76-1.35

55.6 %

1.29

0.92-1.81

 Liver disease

200

33

16.5

0.76

0.52-1.11

50.8 %

0.79

0.52-1.21

 Autoimmune disease

161

39

24.2

1.22

0.85-1.77

0.0 %

1.44

0.95-2.18

 Obesee

1620

337

20.8

1.0

0.9-1.2

0.0 %

0.87

0.73-1.03

Pregnancyf

298

160

53.7

3.45

2.23-5.34

0.0 %

2.08

1.43-3.03

 Associated comorbidity

38

26

68.4

7.07

3.09-16.18

0.0 %

4.29

2.65-6.94

 No comorbidity

260

126

48.5

3.05

2.08-4.47

0.0 %

1.80

1.22-2.66

  1. aStrains considered: A(H3N2), A(H1N1)pdm09 and B/Yamagata
  2. bMinimal sufficient adjustment sets for estimating the exposure or risk factor effect on the risk of admission with influenza vs. all included admissions without underlying conditions or pregnant
  3. cFemale or female non-pregnant vs. male. aORs were adjusted for age, occupational social class group, underlying comorbidity, obesity, influenza vaccination, time to swab, calendar time, and site as a clustering factor
  4. dOne or more underlying conditions or individual comorbidities vs. no comorbidity. aORs were adjusted for sex, occupational social class group, obesity, influenza vaccination, time to swab, calendar time, and site as a clustering factor
  5. eaOR adjusted for sex, age, occupational social class group, influenza vaccination, time to swab, calendar time, and site as a clustering factor
  6. fWomen 15-45 years of age included in Moscow, St. Petersburg, Czech Republic, Turkey and Valencia. aOR adjusted for smoking habits, time to swab, calendar time, comorbidity, and site as a clustering factor. For results stratified by comorbidity, aORs were adjusted by the same covariates and were estimated taking into account the interaction between pregnancy and comorbidity