Skip to main content

Table 2 Characteristics of pregnant admissions by influenza infection status

From: Epidemiology of influenza in pregnant women hospitalized with respiratory illness in Moscow, 2012/2013–2015/2016: a hospital-based active surveillance study

Characteristic

Influenza positive

Influenza negative

OR (95% CI)

P-value

N = 825

N = 923

Age group, n (%)

 15–19 years

27 (3.3)

42 (4.6)

1

 

 20–24 years

153 (18.6)

214 (23.2)

1.11 (0.66–1.88)

0.692

 25–29 years

327 (39.6)

341 (36.9)

1.49 (0.90–2.48)

0.122

 30–34 years

206 (25.0)

214 (23.2)

1.50 (0.89–2.52)

0.128

 35–39 years

89 (10.8)

94 (10.2)

1.47 (0.84–2.59)

0.178

 40–44 years

23 (2.8)

18 (2.0)

1.99 (0.91–4.35)

0.086

Median age in years (range)

28.5 (15–44)

28 (15–44)

1.02 (1.00–1.04)

0.021

Underlying conditions, n (%)

 One or more

136 (16.5)

106 (11.5)

1.52 (1.16–1.99)

0.003

 Cardiovascular disease

28 (3.4)

23 (2.5)

1.37 (0.78–2.40)

0.268

 Chronic obstructive pulmonary disease

12 (1.5)

8 (0.9)

1.68 (0.69–4.14)

0.256

 Asthma

10 (1.2)

6 (0.7)

1.87 (0.68–5.17)

0.227

 Diabetes a

0 (0.0)

3 (0.3)

0.29 (0.00–2.71)

0.294

 Renal impairment

68 (8.2)

54 (5.9)

1.44 (0.99–2.09)

0.053

 Cirrhosis

9 (1.1)

8 (0.9)

1.26 (0.48–3.28)

0.637

 Neuromuscular a

1 (0.1)

0 (0.0)

1.12 (0.03–∞)

0.944

 Neoplasm

2 (0.2)

2 (0.2)

1.12 (0.16–7.95)

0.912

 Rheumatic disease a

0 (0.0)

1 (0.1)

1.12 (0.00–43.63)

1.000

 Antiviral treatment before admission, n (%)

8 (1.0)

11 (1.2)

0.81 (0.32–2.02)

0.652

 Influenza vaccination, n (%)

3 (0.4)

3 (0.3)

0.99 (0.97–1.01)

0.392

Trimester of pregnancy, n (%)

 First (0–13 weeks)

177 (21.5)

221 (23.9)

1

 

 Second (14–26 weeks)

355 (43.0)

372 (40.3)

1.19 (0.93–1.52)

0.162

 Third (27–42 weeks)

291 (35.3)

325 (35.2)

1.12 (0.87–1.44)

0.388

 Gestational age at admission (weeks), median (range)

23 (1–41) b

23 (3–42) c

1.00 (0.99–1.01)

0.872

Smoking habits, n (%)

 Never smoked

563 (68.2)

602 (65.2)

1

 

 Past smoker

225 (27.3)

268 (29.0)

0.90 (0.73–1.11)

0.317

 Current smoker

37 (4.5)

53 (5.7)

0.75 (0.48–1.15)

0.188

Socioeconomic class, n (%)

 Managerial

359 (43.5)

383 (41.5)

1

 

 Skilled

360 (43.6)

425 (46.0)

0.9 (0.74–1.10)

0.324

 Unskilled

34 (4.1)

52 (5.6)

0.7 (0.44–1.10)

0.121

 Other

72 (8.7)

63 (6.8)

1.22 (0.84–1.76)

0.29

Time from onset of symptoms to swabbing, n (%)

 0–2 days

559 (67.8)

541 (58.6)

1

 

 3–4 days

228 (27.6)

280 (30.3)

0.79 (0.64–0.97)

0.027

 5–7 days

38 (4.6)

102 (11.1)

0.36 (0.24–0.53)

0.001

 Days from onset of symptoms to swabbing, median (range)

2 (0–7)

2 (0–7)

0.87 (0.82–0.93)

0.001

  1. aOdds ratio estimated by exact logistic regression
  2. bN = 823
  3. cN = 918