Contributors
Concept and design: Kempen, Hedman, Lindner, Melhus, Nielsen, Sulku,
Gillespie.
Obtained funding: Kempen, Melhus, Nielsen, Sulku, Gillespie.
Acquisition, analysis, or interpretation of data: All authors.
Statistical analysis: Kempen, Hedman, Hadziosmanovic.
Supervision: Melhus, Nielsen, Gillespie.
Administrative, technical, or material support: Lindner, Sulku,
Gillespie.
Drafting of the manuscript: Kempen, Hedman.
Critical revision of the manuscript: Hadziosmanovic, Lindner, Melhus,
Nielsen, Sulku, Gillespie.