Funding for this research was provided by:
The Norwegian Ministry of Education and Research
The Norwegian Directorate of Health
Article History
Received: 22 January 2018
Accepted: 18 June 2018
First Online: 12 July 2018
Compliance with ethical standards
:
: On behalf of all authors, the corresponding author states that there is no conflict of interest.
: The study was approved by the Regional Committees for Medical and Health Research Ethics South East and North and performed in accordance with the ethical standards in the 1964 Declaration of Helsinki and its later amendments. The study participation was based on written informed consent. Parental consent was required for survivors younger than 16 years of age, as stipulated by Norwegian laws.