Method: A systematic search was conducted in the database PubMed and was performed on articles from 2006-2017 with compound search criteria based on the project's goals.
Aðferð: Framkvæmd var kerfisbundin leit í gagnasafninu PubMed með samsettum leitarorðum með markmið verkefnisins í huga og voru notaðar greinar frá árunum 2006-2017.