76 / 87
26. Levels of Evidence and Grades of Recommendations - Oxford Centre for
Evidence
Based
Medicine.
Disponível
em
URL:
http://cebm.jr2.ox.ac.uk/docs/old_levels.htm.27. Wells G, Shea B, O’Connell D, Robertson J, Peterson J, Welch V, et al. The
Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised
studies in meta-analyses.