3.2. Study Selection
The manuscript selection was based on the inclusion criteria: preclinical (in vivo) and clinical studies involving the use of HCQ and combinations, only articles published in English and containing keywords in the title or in the abstract were selected. Other review articles, meta-analysis, retrospective studies, abstracts, conferences, editorials, letters, conference proceedings, manuscripts without full text available or articles that did not meet the inclusion criteria were not included in this systematic review. For selecting the sources, three independent investigators (I.F., F.L., and M.P.) first selected the articles according to the title and abstract and then by analyzing the full-texts. In cases of non-consensus, authors tried to resolve any disagreements by discussion or, if necessary, two more independent reviewers were consulted (L.M. and N.D.T.). The selected articles were carefully reviewed with the aim of identify or exclude the manuscripts that did not fit the criteria described above. Additional papers were added to this review after the analysis of the bibliography from the included articles.