From: Strategies for maximizing consent rates for child dental health surveys: a randomised controlled trial
FISA&DM
FIS
Promotion of the survey
Multiple letters
Control
N
60
67
68
64
66
Mean consent rate (%) (95%CI)
47 (41 to 53)
54 (49 to 59)
58 (54 to 62)
63 (58 to 69)
57 (52 to 62)
Standard deviation
(22)
(20)
(17)
(21)