Article History
Received: 29 March 2018
Accepted: 27 July 2018
First Online: 8 August 2018
Ethics approval and consent to participate
: The study protocol was approved by the Tallinn Medical Research Ethics Committee (No. 1123, August 13, 2015). According to the Estonian legislation (Personal Data Protection Act, RT I 2007, 24, 127), participant consent was not necessary.
: Not applicable.
: The authors declare that they have no competing interests.
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