**2.4 Ethical considerations**

Participation in the study was voluntary, and the participants along with their employers gave their written consent for the participation and data collection. According to national regulation, no statement from an ethics committee was needed, because the study did not directly focus on patients. Nor was a notification to the Danish Data Protection Agency necessary, because the study does not contain confidential or sensitive personal data. The personal data has been processed in accordance with the Danish Processing of Personal Data Act and subsequent legislation.
