Table 4 Factors associated with having at least one AGE episode during a winter season (univariate and multivariate analysis) among the 8811 participants-season, using the AGE definition of the WHO expert group

Variable

N*

Case N (%)

OR [IC 95%]

p-value

OR [IC 95%]

p-value

Season

2014–2015

3905

574 (15%)

–

< 0.001

–

< 0.001

2015–2016

4906

682 (14%)

0.92 [0.82–1.03]

0.92 [0.82–1.04]

2016–2017

5164

568 (11%)

0.71 [0.63–0.80]

0.68 [0.60–0.78]

Gender

Female

8381

1168 (14%)

–

< 0.001

–

< 0.001

Male

5594

656 (12%)

0.82 [0.74–0.92]

0.81 [0.72–0.91]

Age (years)

15 to 59

7171

1018 (14%)

–

–

<  10

461

146 (32%)

2.82 [2.27–3.51]

2.33 [1.35–4.02]

10 to 14

347

60 (17%)

1.26 [0.93–1.71]

< 0.001

1.09 [0.60–1.95]

< 0.001

≥ 60

5978

596 (10%)

0.67 [0.59–0.75]

0.70 [0.61–0.80]

Household composition

Living with adults only

7266

833 (11%)

–

–

Living alone

2217

309 (14%)

1.22 [1.05–1.43]

< 0.001

1.20 [1.03–1.41]

0.052

Living with ≥1 child

4443

675 (15%)

1.37 [1.22–1.53]

0.95 [0.83–1.10]

Main activity

Working

6595

905 (14%)

–

Student

1287

262 (20%)

1.61 [1.37–1.89]

Unemployed

370

53 (14%)

1.03 [0.75–1.42]

Retired

4959

494 (10%)

0.69 [0.61–0.78]

Stay at home/Sick leave

506

56 (11%)

0.79 [0.58–1.07]

< 0.001

Level of education

High school diploma

2564

316 (12%)

–

–

Middle school diploma

2211

221 (10%)

0.80 [0.66–0.97]

0.78 [0.64–0.95]

Higher education

7488

1048 (13%)

1.05 [0.91–1.22]

< 0.001

1.00 [0.86–1.16]

0.031

Not concerned

961

228 (24%)

2.23 [1.82–2.74]

1.19 [0.71–1.99]

Place of residency

Rural

2696

360 (13%)

–

Urban

11,279

1464 (13%)

0.97 [0.85–1.10]

0.605

Use of public transportation

No

11,787

1450 (13%)

–

Yes

2188

284 (13%)

0.98 [0.85–1.13]

0.815

Pets at home

None

7689

933 (12%)

–

–

At least one

6264

889 (14%)

1.20 [1.08–1.33]

< 0.001

1.18 [1.06–1.32]

0.009

Contact with patients

No

12,556

1603 (13%)

–

Yes

1424

221 (16%)

1.26 [1.08–1.48]

0.003

Contact with elderly

No

12,551

1653 (13%)

–

Yes

1424

171 (12%)

0.90 [0.76–1.07]

0.226

Contact with a group of people

No

9535

1212 (13%)

–

Yes

4440

612 (14%)

1.10 [0.99–1.22]

0.091

Contact with children

No

10,587

1489 (12%)

–

Yes

3388

335 (16%)

1.33 [1.18–1.49]

< 0.001

Common cold frequency

Never

6076

634 (10%)

–

–

Rare

5031

652 (13%)

1.24 [1.10–1.39]

< 0.001

1.14 [1.01–1.29]

< 0.001

Often

2510

500 (20%)

2.05 [1.79–2.34]

1.58 [1.37–1.82]

Smoking status

Non smoker

12,466

1624 (13%)

–

Smoker

1493

198 (13%)

1.02 [0.86–1.20]

0.860

Comorbidities^a

No comorbidities

10,987

1407 (13%)

–

–

At least one comorbidity

2988

417 (14%)

1.10 [0.97–1.25]

0.136

1.18 [1.03–1.36]

0.004

Treated asthma

841

138 (16%)

1.32 [1.08–1.62]

0.008

Treated diabetes

526

75 (14%)

1.10 [0.83–1.46]

0.508

Treated heart condition

1400

172 (12%)

0.94 [0.79–1.12]

0.522

Treated kidney condition

87

9 (10%)

0.73 [0.33–1.59]

0.425

Treated immunosuppression

386

68 (18%)

1.43 [1.07–1.91]

0.017

Treated pulmonary condition

365

52 (14%)

1.08 [0.80–1.45]

0.633

Respiratory allergy

None

9254

1131 (12%)

–

–

At least one

4721

693 (15%)

1.23 [1.10–1.37]

< 0.001

1.20 [1.07–1.35]

< 0.001

BMI

Normal weight (18.5 to 24[)

6923

976 (12%)

–

–

Underweight (<  18.5)

1126

93 (15%)

1.26 [1.00–1.60]

0.99 [0.77–1.26]

Overweight (25 to 29)

3340

459 (12%)

1.00 [0.88–1.14]

0.005

1.16 [1.02–1.33]

< 0.001

Obese (≥ 30)

1347

240 (16%)

1.30 [1.10–1.54]

1.35 [1.13–1.61]