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Article History

Received: 15 November 2017

Accepted: 29 May 2018

First Online: 7 June 2018

Ethics approval and consent to participate

: This was a registry study with an observational study design, and no clinical interventions were performed. In Northern Finland, including the Kainuu and Länsi-Pohja hospital districts, the Regional Ethics Committee is centralized in the Northern Ostrobothnia Hospital District, which granted approval for the study. Permission to perform this study was also obtained from both Hospital Districts and the Office of Data Protection Ombudsman. Due to the study design and the large sample size, the consent of the individual patient was not required.

: MH reports EVO research funding to Oulu University Hospital. TS and TA declare that they have no financial or any other conflicts of interests.

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