Text and Data Mining valid from 2020-03-30
Received: 17 December 2018
Accepted: 18 March 2020
First Online: 30 March 2020
Ethics approval and consent to participate
: The procedures followed in this study were in accordance with the Helsinki Declaration of 1975, as revised in 2000. The study was generally approved by the local research ethics committee, and no further specific approval was demanded because the study is an outcome study, which according to the Danish law “Act on a Biomedical Research Ethics Committee System and the Processing of Biomedical Research Projects”, Part 3 “Notification and authorization”: Questionnaire-based projects and register research projects shall only be notified to a regional committee if the project also involves human biological material. The study was registered in The Danish data Protection Agency and ExternalRef removed Identifier: (NCT01554748).
: Not applicable
: The authors declare that they have no competing interests.