Table 5 Logistic Regression Analysis of the Risk Factors Associated with the Mechanical Complication and Acute Respiratory Distress Syndrome (ARDS) among Patients with Influenza A(H1N1)pdm09 Virus Infection.

Gender, male

1.5 (0.8–2.9)

0.3

6B/6B.1/6B.2 season

2.6 (1.2–5.6)

5.0 (2.6–9.96)

<0.001

5.5 (1.9–15.9)

0.002

Age group

0.02

0.9

   ≤5

Reference

—^a

—^a

—^a

—^a

   6–18

0.8 (0.2–3.4)

—^a

—^a

—^a

—^a

   19–49

4.0 (1.3–12.6)

Reference

Reference

   50–64

3.9 (1.1–13.8)

2.8 (1.3–5.9)

0.007

0.8 (0.2–2.6)

0.7

   ≥65

9.6 (2.3–39.6)

2.1 (0.8–5.5)

0.1

0.7 (0.16–2.9)

0.6

Onset to presentation

1.04 (0.96–1.13)

1.09 (1.03–1.16)

0.006

1.1 (0.98–1.25)

0.1

Underlying conditions

5.5 (2.34–13.1)

10.6 (5.2–21.4)

<0.001

2.1 (0.6–6.7)

0.2

Obesity

2.4 (0.88–6.6)

11.7 (5.4–25.3)

<0.001

3.0 (1.04–8.7)

0.04

Smoking

2.24 (0.7–7.3)

16.7 (7.7–36.2)

<0.001

2.9 (0.9–9.7)

0.09

Alcoholism

8.2 (0.6–109.1)

32.2 (5.7–181.6)

<0.001

3.8 (0.4–39.3)

0.27

Antiviral therapy

<0.001

0.05

   No antiviral therapy

Reference

Reference

Reference

   Within 48 hours

3.4 (0.8–14.8)

12.3 (1.6–94.6)

0.02

5.2 (0.2–124.6)

0.3

   After 48 hours

8.5 (2.1–33.9)

41.7 (5.6–310.5)

<0.001

13.4 (0.7–268.9)

0.09