Funding for this research was provided by:
Greta och Johan Kocks stiftelser
Alfred Österlunds Stiftelse
Received: 28 March 2018
Accepted: 13 February 2019
First Online: 18 February 2019
Ethics approval and consent to participate
: All aspects of the study including access and use the data were approved by the Lund University Ethics committee (Dnr 2014/276). The need for individual informed consent was waived by the Ethics committee. The study was advertised in the major newspapers where a possibility to opt-out was offered. This is a principle used in Sweden for population-wide studies using non-identifiable register data (ExternalRef removed).
: Not applicable.
: AAK is an associate editor of BMC Musculoskeletal Disorders. The other authors declare that they have no conflict of interest.
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