Laine, Merja K. https://orcid.org/0000-0002-1848-1514
Kautiainen, Hannu
Gissler, Mika
Pennanen, Pirjo
Eriksson, Johan G.
Funding for this research was provided by:
Helsingin ja Uudenmaan Sairaanhoitopiiri
Article History
Received: 22 November 2020
Accepted: 8 February 2021
First Online: 16 February 2021
Ethics approval and consent to participate
: The study has been approved by the ethics committee of the Hospital District of Helsinki and Uusimaa, Finland (356/13/03/03/2015, 2 November 2015), and the health authority of the city of Vantaa, Finland. Finnish Institute for Health and Welfare (THL), Statistics Finland, the Finnish Tax Administration, and the Social Insurance Institution has given permission to use register data in the study. Informed consents were not required because the study is an observational register-based cohort study and no study participants were contacted.
: Not applicable.
: The authors declare that they have no competing interests.