Authors’ contributions
Guarantor: Mr Risto had full access to all of the data in the study and takes responsibility for the integrity study. Study concept and design: All co-authors. Interpretation of results: All co-authors. Drafting of the manuscript: Risto. Figures and tables: Risto and Nordenvall. Critical revision of the manuscript for important intellectual content: All co-authors. Final approval of the version to be submitted: All co-authors.