Funding for this research was provided by:
Danish National Innovation Foundation
Received: 22 August 2017
Accepted: 27 March 2018
First Online: 20 April 2018
Ethics approval and consent to participate
: In compliance with Danish law, this study was approved by the Danish Data Protection agency (J No 2013–41-2036) and the Danish National Board of Health (J No 3–3013-355). No further ethical approval is needed for register-based research in Denmark. Data was anonymized immediately after linkage.
: The study is registered with and approved by the Danish Data Protection Agency (J NO 2013–41-2036). Access to patient records is approved by the Danish Health and Medicines Authority (J NO 3–30013-355/1).
: The authors declare that they have no competing interest.
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