Remove barriers to participation The most obvious barrier is financial; thus wherever possible we provide transportation to and from the Dunedin Research Unit, accommodation, and meals. We also provide a letter to the Study member, addressed to their employer, explaining the value of the study and seeking their co-operation in allowing our Study members to attend the assessment without loss of income. In rare circumstances people who wish to participate but cannot travel to Dunedin (e.g. work commitments, incarceration) are visited by two interviewers in the field (amounting to 1–2 % each phase).
