https://trialsjournal.biomedcentral.com/articles/10.1186/1745-6215-9-52
https://trialsjournal.biomedcentral.com/articles/10.1186/1745-6215-9-51
https://trialsjournal.biomedcentral.com/articles/10.1186/1745-6215-9-50
https://trialsjournal.biomedcentral.com/articles/10.1186/1745-6215-9-49