Fig. 1From: A randomised controlled trial comparing opt-in and opt-out home visits for tracing lost participants in a prospective birth cohort studyParticipant flow diagram for the randomised controlled trial showing the number of eligible participants, random selection of participants from those eligible, random allocation to the opt-in and opt-out arms of the trial, numbers withdrawn after randomisation, and numbers who opted in or out in each arm. It also shows outcomes in each arm of the trial - numbers traced, who consented to continue in ALSPAC, and who consented to data linkage (YPs only)Back to article page