Table 3 Factors associated with at least one ILI episode (ILI_ECDC) during six influenza epidemic periods, GrippeNet.fr

Season

2012/13

2943

866 (29%)

Ref.

<10⁻⁴

Ref.

<10^− 4

2013/14

4140

469 (11%)

0.31 [0.27;0.34]

0.30 [0.26;0.33]

2014/15

4428

886 (20%)

0.59 [0.54;0.66]

0.60 [0.54;0.67]

2015/16

4780

829 (17%)

0.50 [0.45;0.55]

0.50 [0.45;0.56]

2016/17

4204

787 (19%)

0.54 [0.49;0.60]

0.57 [0.51;0.63]

2017/18

4158

855 (21%)

0.61 [0.55;0.68]

0.64 [0.57;0.71]

 Gender

Male

9742

1623 (17%)

Ref.

<10⁻⁴

Ref.

<10⁻⁴

Female

14,911

3069 (21%)

1.30 [1.20;1.40]

1.29 [1.20;1.40]

 Age

[45–65)

9940

1959 (20%)

Ref.

<10⁻⁴

Ref.

<10^− 4

[0–5)

306

111 (36%)

2.27 [1.78;2.89]

3.12 [2.05;4.68]

[5–15)

1133

279 (25%)

1.32 [1.12;1.55]

1.53 [1.17;2.00]

[15–45)

5948

1309 (22%)

1.15 [1.06;1.25]

1.13 [1.03;1.25]

[65–75)

6003

885 (15%)

0.71 [0.65;0.78]

0.88 [0.77;1.01]

≥75

1300

146 (11%)

0.54 [0.45;0.65]

0.70 [0.56;0.87]

 Household composition

Living alone

3917

731 (19%)

Ref.

<10⁻⁴

NS

NS

Living with ≥1 child

7712

1714 (22%)

1.25 [1.12;1.40]

Living with adults only

12,953

2234 (17%)

0.92 [0.83;1.02]

 Occupation

Working

11,587

2432 (21%)

Ref.

<10⁻⁴

Ref.

<10⁻²

Student

2162

543 (25%)

1.25 [1.11;1.41]

1.02 [0.83;1.26]

Unemployed

575

138 (24%)

1.18 [0.96;1.46]

1.18 [0.95;1.46]

Retired

8932

1299 (15%)

0.64 [0.59;0.70]

0.80 [0.70;0.91]

0.84 [0.70;1.02]

Stay at home/ Sick leave

993

191 (19%)

0.89 [0.74;1.07]

 Place of residency

Rural

4840

906 (19%)

Ref.

0.67

–

–

Urban

19,813

3786 (19%)

1.02 [0.93;1.12]

 Use of public transport

No

20,843

3855 (18%)

Ref.

<10⁻⁴

Ref.

<10⁻²

Yes

3810

837 (22%)

1.22 [1.12;1.34]

1.17 [1.07;1.29]

 Pets at home

None

13,492

2377 (17%)

Ref.

<10⁻⁴

Ref.

<10^− 4

At least one

11,118

2311 (20%)

1.21 [1.13;1.30]

1.18 [1.09;1.27]

 Contacts with patients

No

22,163

4154 (19%)

Ref.

0.01

NS

NS

Yes

2490

538 (22%)

1.17 [1.04;1.30]

 Contacts with elderly

No

22,153

4234 (19%)

Ref.

0.41

–

–

Yes

2496

458 (18%)

0.96 [0.86;1.07]

 Contacts with a group of people

No

16,795

3047 (18%)

Ref.

<10⁻⁴

NS

NS

Yes

7858

1645 (21%)

1.17 [1.09;1.25]

 Contacts with children

No

18,722

3342 (18%)

Ref.

<10⁻⁴

NS

NS

Yes

5931

1350 (23%)

1.33 [1.23;1.43]

 Influenza vaccination (current season)

No

16,083

3240 (20%)

Ref.

<10⁻⁴

Ref.

0.04

Yes

8554

1450 (17%)

0.82 [0.76;0.88]

0.91 [0.84;0.99]

 Influenza vaccination (last season)

No

15,190

3083 (20%)

Ref.

<10⁻⁴

NS

NS

Yes

9305

1575 (17%)

0.81 [0.75;0.87]

 Smoking status

Non smoker

21,995

4176 (19%)

Ref.

0.55

–

–

Smoker

2630

514 (20%)

1.04 [0.92;1.16]

 Chronic treatment for at least one comorbidity^c

No comorbidity

19,425

3648 (19%)

Ref.

Ref.

<10⁻³

At least one comorbidity

5228

1044 (20%)

1.08 [0.99;1.17]

0.10

1.20 [1.09;1.32]

Asthma

1449

384 (27%)

1.53 [1.33;1.75]

< 10⁻⁴

Diabetes

941

156 (17%)

0.85 [0.70;1.04]

0.12

Heart diseases

2473

420 (17%)

0.88 [0.78;0.99]

0.03

Kidney diseases

152

24 (16%)

0.77 [0.48;1.25]

0.29

Immunosuppression

655

140 (21%)

1.13 [0.91;1.39]

0.26

Pulmonary diseases

635

161 (25%)

1.40 [1.13;1.73]

<10⁻²

 Respiratory allergy

None

16,400

2887 (18%)

Ref.

<10⁻⁴

Ref.

<10⁻⁴

At least one

8253

1805 (22%)

1.29 [1.20;1.39]

1.27 [1.18;1.37]

 BMI

Normal weight [18.5;25[

14,000

2563 (18%)

Ref.

<10⁻²

Ref.

<10⁻⁴

Underweight < 18.5

1053

201 (19%)

1.04 [0.88;1.25]

0.92 [0.77;1.11]

Overweight [25;30[

6571

1241 (19%)

1.04 [0.96;1.13]

1.18 [1.08;1.29]

Obese ≥30

2629

586 (22%)

1.26 [1.12;1.40]

1.28 [1.14;1.44]