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 referred to interviewer for home visit
Opt-in N = 15
Opt-out N = 139
Participant traceable
6 (40 %)a
77 (55 %)
Discussion took place
4 (27 %)a
54 (39 %)
Consent to ALSPAC given
46b(33 %)