Table 1 Differences between patients with and without headache

Female sex

3856 (49.2%)

1221 (47.8%)

2635 (50.0%)

0.068

Cardiovascular disorders

193 (2.5%)

64 (2.5%)

129 (2.4%)

0.878

Diabetes

211 (2.7%)

41 (1.6%)

170 (3.2%)

 < 0.001

COPD

79 (1.0%)

17 (0.7%)

62 (1.2%)

0.034

Cancer

65 (0.8%)

16 (0.6%)

49 (0.9%)

0.165

Kidney disorders

21 (0.3%)

3 (0.1%)

18 (0.3%)

0.072

Hepatic disorders

14 (0.2%)

4 (0.2%)

10 (0.2%)

0.745

Obesity

67 (0.9%)

15 (0.6%)

52 (1.0%)

0.072

Vaccination

337 (4.3%)

112 (4.4%)

225 (4.3%)

0.814

Onset within 48 h

4573 (58.4%)

1398 (54.7%)

3175 (60.2%)

 < 0.001

Epidemiological contact

2964 (37.8%)

884 (34.6%)

2080 (39.4%)

 < 0.001

Sudden onset

7325 (93.5%)

2308 (90.3%)

5017 (95.1%)

 < 0.001

Fever

7427 (94.8%)

2361 (92.3%)

5066 (96.0%)

 < 0.001

Shivering

5129 (65.5%)

1188 (46.5%)

3941 (74.7%)

 < 0.001

Asthenia

6009 (76.7%)

1548 (60.5%)

4461 (84.6%)

 < 0.001

Myalgia

5248 (67.0%)

1158 (45.3%)

4090 (77.5%)

 < 0.001

Cough

6695 (85.5%)

2135 (83.5%)

4560 (86.4%)

0.001

Dyspnea

736 (9.4%)

208 (8.1%)

528 (10.0%)

0.008

Nasopharyngeal erythema

6838 (87.3%)

2128 (83.2%)

4710 (89.3%)

 < 0.001

Gastrointestinal symptoms

2123 (27.1%)

628 (24.6%)

1495 (28.3%)

 < 0.001

Oropharyngeal swab obtention

2113 (27.0%)

668 (26.1%)

1445 (27.4%)

0.235

Confirmed infection

1194/2113 (56.5%)

376/668 (56.3%)

818/1445 (56.6%)

0.985

A subtype

809/1194 (67.8%)

257/376 (68.4%)

552/818 (67.5%)

0.764

B subtype

385/1194 (32.2%)

119/376 (31.6%)

266/818 (32.5%)

0.823

Hospital referral

49 (0.6%)

25 (1.0%)

24 (0.5%)

0.006

Scholar absenteeism

2205/6624 (33.3%)

765/2315 (33.0%)

1440/4309 (33.4%)

0.759

Medical leave

591 (7.5%)

120 (4.7%)

471 (8.9%)

 < 0.001