Received: 15 January 2021
Accepted: 12 April 2021
First Online: 6 May 2021
: The study used secondary data from registers. In Finland, an ethical review statement is not required for studies based solely on administrative register data (Finnish National Board on Research Integrity 2019). Good scientific practice and data protection procedures and regulations were followed. City of Oulu, Social Insurance Institution of Finland (Kela), Statistics Finland and Finnish Institute of Health and Wellfare (for Care Register for Health Care) provided permission for the use of the register data.
: Not applicable.
: The authors’ declare that they have no competing interests.