3). Contact was initiated by eligible families seeking enrolment or during ALSPAC community outreach and promotion activities. Due to the nature of these recruitment methods, it is not possible to determine how many individuals were ‘invited’ during recruitment Phases II and III. Where recruitment occurred in Phases II and III, ALSPAC have not been able to collect the pregnancy, infancy and early childhood data that were collected from parental self-completed questionnaires from the sample recruited during pregnancy (Phase I).
