Table 1 Overview of RDS Recruitment for the Engage Study

Sample size

753

517

1179

Interview date earliest

16-Feb-17

16-May-17

07-Feb-17

Interview date latest

31-Jul-19

09-Aug-19

15-Jun-18

Time difference in days

895

815

493

# of seeds

117

96

27

# of productive seeds

71

53

21

% of productive seeds among seeds

60.7%

55.2%

77.8%

# of RDS coupons given to the participant

4313

3096

6753

Median

Q1, Q3

Median

Q1, Q3

Median

Q1, Q3

# of direct recruits per seed

1

0, 2

1

0, 2

2

1, 3

Chain length per RDS chain/seed*

1

0, 3

1

0, 1.5

2

1, 7

Chain size per RDS chain/seed*

2

1, 6

2

1, 3.5

7

2, 39

Participant network size

30

14, 100

37

15, 100

30

15, 80

Wave at which participant was recruited (participant-level)*

2

1, 4

2

1, 4

6

4, 9

Total number of participants in recruitment chain (participant-level)*

17

7, 57

23

5, 61

274

75, 413