Table 3 Baseline participant demographics and self-reported method of recruitment

Age range (years), n (%)

 0–13

15 (4.9%)

2 (0.6%)

2 (0.6%)

1 (0.3%)

4 (1.4%)

6 (2%)

 14–19

104 (35.1%)

14 (4.7%)

2 (0.7%)

81 (27.4%)

0

7 (2.3%)

 20–29

90 (30.4%)

67 (22.6%)

3 (1%)

4 (1.4%)

1 (0.3%)

15 (5.1%)

 30–39

43 (15%)

30 (10.1%)

7 (2.4%)

2 (0.7%)

0

4 (1.3%)

 40–49

16 (5.4%)

5 (1.7%)

6 (2%)

0

2 (0.7%)

3 (1%)

 50–59

13 (4.3%)

3 (1%)

9 (3%)

0

0

1 (0.3%)

 60–69

10 (3.3%)

0

9 (3%)

0

0

1 (0.3%)

 70–74

5 (1.6%)

0

5 (1.6%)

0

0

0

Ethnicity, n (%)

 White

228 (77%)

92 (31.1%)

41 (13.9%)

57 (19.3%)

7 (2.3%)

31 (10.4%)

 Asian

36 (12.1%)

19 (6.4%)

1 (0.3%)

13 (4.4%)

0

3 (1%)

 Mixed background

15 (5.1%)

8 (2.7%)

0

6 (2%)

0

1 (0.3%)

 Black

13 (4.4%)

0

0

11 (3.7%)

0

2 (0.7%)

 Another ethnic group

4 (1.4%)

2 (0.7%)

1 (0.3%)

1 (0.3%)

0

0

Gender, n (%)

 Male

77 (26%)

49 (16.6%)

11 (3.7%)

6 (2%)

2 (0.7%)

9 (3%)

 Female

210 (71%)

69 (23.3%)

32 (10.8%)

76 (25.7%)

5 (1.7%)

28 (9.5%)

 Other

3 (1%)

2 (0.7%)

0

1 (0.3%)

0

0

 Prefer not to say

6 (2%)

1 (0.3%)

0

5 (1.7%)

0

0