Study Selection
Two reviewers will screen all the titles and/or abstracts independently
and if a disagreement is reached on whether a study should be included
in the full-text eligibility assessment; appropriate discussion between
the two reviewers will follow, and if disagreement persists then a third
independent reviewer will be invited to reach a consensus. The
eligibility of each full-text study to be included in the systematic
review according to the aforementioned characteristics will be assessed
independently by the two reviewers and any disagreement will be solved
by the independent third reviewer to reach consensus. All the required
information for this systematic review was found in the studies. A
summary of the selection process according to PRISMA guidelines for
systematic reviews is presented in Figure 1. Initially the search
retrieved 984 studies, from which 242 duplicates were removed resulting
in 742 studies. From the remaining abstracts and/or titles 706 records
were excluded according to eligibility criteria, a further 32 from the
36 full-text reviews were excluded based on not matching
inclusion/exclusion criteria. Four studies remained at the end of the
selection process.