Response rates and selection problems, with emphasis on mental health variables and DNA sampling, in large population-based, cross-sectional and longitudinal studies of adolescents in Norway

• Main Authors: Lien Lars (Author), Green Kristian (Author), Sagatun Åse (Author), Bjertness Espen (Author), Søgaard Anne (Author), Selmer Randi (Author)
• Format: Book
• Published: BMC, 2010-10-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

<p>Abstract</p> <p>Background</p> <p>Selection bias is a threat to the internal validity of epidemiological studies. In light of a growing number of studies which aim to provide DNA, as well as a considerable number of invitees who declined to participate, we discuss re...