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First Online: 15 October 2020

Declarations

:

: Open access funding provided by Umea University. This study was supported by grants from The Swedish Research Council (Grant number 2016-02589).

: None of the authors have any competing interests to declare.

: All participants provided written informed consent to partake in the study.

: MB, PN and AN conceived and designed the study, MB drafted the manuscript and analyzed the data. PN retrieved the register data and created the combined data file. MB, PN, JN and AN interpreted the data. MB, PN, JN and AN revised the work critically for important intellectual content. All authors agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All authors approved the final version of the manuscript to be published.

: The datasets analysed during the current study are not publicly available in accordance with the General Data Protection Regulation, but a de-identified data set may be available from the corresponding author on reasonable request.

: The present study was approved by the Regional Ethical Review Board in Umeå, Sweden (no. 07-031M with extensions) and was conducted in accordance with the World Medical Association’s Declaration of Helsinki.

: All participants provided verbal and written informed consent to partake in the study.

: Not applicable.

: Not applicable.