The DNBC Puberty Follow-up started in 2012 and was brough to an end in February 2021. 22.500 children born between 2000 and 2003 were asked to complete a short questionnaire every 6 months. The participation rate is close to 70%.
Data documentation and contact procedure
In the DNBC Puberty Follow-up paper letters or e-mail invitations were sent every 6 months to the mothers of puberty cohort participants until they turned 15, at which point the young participants were contacted directly.
The invitation procedure consisted of an invitation (paper letter of e-mail, if we had the email-address). Non-responders received a reminder 14 days after the invitations (paper or email) and a 2nd reminder another 14 days later. A last reminder was sent yet 14 days after the 2nd reminder. This last reminder was a paper letter in case previous emails had not reached the participant.
Puberty Follow-up Code books in Danish and English