Table 1 Characteristics of the participants in three cross-sectional surveys in 2013–2015 and the respective cohorts in 2013–2014 and 2014–2015.

From: Avian influenza A(H7N9) and (H5N1) infections among poultry and swine workers and the general population in Beijing, China, 2013–2015

Characteristic

Cross-sectional surveys

P value*

Cohorts (Year)

P value*

November 2013

April 2014

April 2015

2013–2014 (Nov 2013–Apr 2014)

2014–2015 (Apr 2014–Apr 2015)

Participant category

   

<0.001

  

<0.001

 Poultry workers

1258 (33.2)

1056 (30.2)

1123 (34.5)

 

791 (30.9)

512 (25.4)

 

 Swine workers

1332 (35.1)

1254 (35.8)

998 (30.7)

 

862 (33.6)

568 (28.2)

 

 General population

1200 (31.7)

1188(34.0)

1135 (34.9)

 

910 (35.5)

932 (46.3)

 

Sex

   

0.051

  

0.529

 Male

1933 (51.0)

1686 (48.3)

1595 (49.0)

 

1224 (47.8)

941 (46.8)

 

 Female

1855 (49.0)

1807 (51.7)

1658 (51.0)

 

1338 (52.2)

1068 (53.2)

 

Age group

   

0.907

  

0.152

 <50 years

2200 (58.1)

2018 (57.8)

1871 (57.6)

 

1435 (56.1)

1085 (54.0)

 

 ≥50 years

1585 (41.9)

1471 (42. 2)

1377 (42.4)

 

1124 (43.9)

926 (46.0)

 

Having underlying disease

   

<0.001

  

0.121

 No

3489 (92.1)

3278 (93.7)

2950 (90.6)

 

2349 (91.7)

1868 (92.9)

 

 Yes

301 (7.9)

219 (6.3)

305 (9.4)

 

214 (8.3)

143 (7.1)

 

Total

3790 (100)

3498 (100)

3256 (100)

2563 (100)

2012 (100)

  1. Note. Data are expressed as proportion (%) of participants, unless otherwise indicated.
  2. *Compared using Pearson’s χ2 test.