Table 1 Participation in All Phases of the Study

Total number of invited participants

21

19

40

39

119

Phase I

Number of Phase I participants

15

12

33

31

91

Participation rate in Phase I

71%

63%

83%

80%

77%

Phase II

Number of participants posting comments in Phase II

9

6

25

16

56

% of active discussion participants

60%

50%

76%

52%

60%

Total number of discussion threads

7

6

16

11

10

Average number of threads initiated per participant

.77

1

.64

.68

.77

Total number of discussion comments

18

21

89

45

43

Average number of comments per participant

2

3.5

3.6

2.8

3

Range of number of comments per participant

1-5

1-6

1-9

1-9

1-9

Phase III

# of Phase III participants

10

10

32

27

79

Participation rate in Phase III

67%

83%

97%

87%

87%

Participation rate in all phases

48%

53%

80%

69%

66%