Study selection
Once the search was done, two authors, MC and MP, applied separately the
eligibility criteria to decide which studies include. Any disagreement
between the authors was solved through discussion with a third author,
EM, to try to reach an agreement. In case of not getting access to a
complete text or abstract, we attempted to get in contact with the main
investigator to get a copy of the study. With the results of the search
in each base and with the subsequent eligibility criteria application a
flow chart was made.