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Article History

Received: 14 February 2020

Accepted: 6 June 2020

First Online: 24 June 2020

Ethics approval and consent to participate

: This study only uses anonymized data, and permission for storage and processing of data for research purposes has been obtained from the research ethics committee at the National Board of Health and Welfare.

: Not applicable.

: The authors declare that they have no competing interests.