From: A randomised controlled trial comparing opt-in and opt-out home visits for tracing lost participants in a prospective birth cohort study
Number of participants sent an invitation letter
Opt-in N = 145
Opt-out N = 139
Returned to sender
12 (8 %)
14 (10 %)
Opted-in
3 (2 %)
N/A
Referred for home visit
15 (10 %)a
139 (100 %)