Funding for this research was provided by:
Received: 26 May 2021
Accepted: 10 January 2022
First Online: 28 January 2022
: The study was approved by the Swedish Ethical Review Authority (approval number 2019–04282, date of issue 10th of September 2019) and was performed in accordance with the Declaration of Helsinki. Informed consent was waived by Swedish Ethical Review Authority because of the register-based design of this study. The data we have used is manually registered in a specific national quality register separate from patients’ medical records. Use of data is regulated by the Swedish patient data act, in the part that applies to national quality registers. In order to be registered in a quality register, it is required that the patient is informed and given the opportunity to opt out. The information must include that the data may be used for research after approval from a research ethical board. The research ethical board decides if consent is required or not, and if data should be anonymized. In our case the decision was made that no further information or consent is required, and that data must be anonymized.
: Not applicable.
: The authors declare no competing interests in relation to the study.