Table 1 Participants’ baseline characteristics for both the hydroxychloroquine and placebo group

Sex, female

93

73.2

104

73.2

Age (mean, SD)

40.3

(12.8)

39.6

(11.2)

Country of origin

 Spain

112

88.2

126

88.7

 Other European countries

0

4

2.8

 Latin America

14

11.0

12

8.5

 North Africa

1

0.8

0

Professional category

 Medical Doctor

53

42.1

67

47.2

 Nurse

35

27.8

40

28.2

 Nurse Assistant

12

9.5

12

8.5

 Administrative

10

7.9

10

7.0

 Other

16

12.7

13

9.2

Smoking

17

13.8

21

14.9

Comorbidities

 Any

42

33.1

41

28.9

 Diabetes mellitus

1

0.8

0

 Hypertension

3

2.4

2

1.4

 Chronic respiratory condition

2

1.6

5

3.5

 Dyslipidemia

4

3.1

3

2.1

 Hyperthyroidism

6

4.7

7

4.7

 Allergy

3

2.4

2

1.4

 Dermatological condition

5

3.9

2

1.4

 Gastrointestinal/liver conditions

2

1.6

5

3.5

 Gynecological conditions

2

1.6

4

2.8

 Psychological disease

2

1.6

2

1.4

 Neurological disease

1

0.8

3

2.1

 Other

16

12.6

8

5.6

Immunosuppression

0

0

Chronic treatment

 Any

34

26.8

40

28.2

 Antidiabetics

0

1

0.7

 Antihypertensives

1

0.8

2

1.4

 Statins

3

2.4

1

0.7

 Bronchodilators

2

1.6

1

0.7

 Contraceptives

9

7.1

11

7.7

 Levothyroxine

6

4.7

9

6.3

 Proton pump inhibitors

2

1.6

5

3.5

 Other

5

3.9

4

2.8

History of vaccination

 Haemophilus

9

7.8

8

6.2

 Pneumococcal

5

4.2

9

6.7

 Influenza

85

68.5

92

64.8