Received: 3 June 2019
Accepted: 23 October 2019
First Online: 11 November 2019
Ethics approval and consent to participate
: This project was approved by the Stockholm Ethics Review Board (2014/1288–31/4). Individual consent was not needed for the use of patient chart data in this study. Ethical considerations of this and other register-based research have been described elsewhere [CitationRef removed]. No administrative permissions were required to access the raw data.
: Not applicable.
: The authors declare that they have no competing interests.