Naumburg, Estelle
Söderström, Lars
Article History
Received: 28 August 2018
Accepted: 13 August 2019
First Online: 17 August 2019
Ethics approval and consent to participate
: The study was approved by the Regional Ethics Committee, Umeå University (D2011–396-31 M). The study is based on register data, and individual informed consent from each participant is not required by waiver from the ethical committee and national guidelines.
: Not applicable. The study is based on register data, and individual informed consent from each participant is not required by waiver from the ethical committee and national guidelines.
: The authors declare that they have no competing interests.