Foram revisados artigos nas bases de dados do MEDLINE (Pub-Med) e outras fontes de pesquisa, sem limite de tempo. A estratégia de busca utilizada baseou-se em perguntas estruturadas na forma P.I.C.O. (das iniciais "Paciente", "Intervençao", "Controle", "Outcome").Articles in the MedLine (PubMed) database and other research sources were reviewed, with no age limit. The search strategy used was based on structured questions in the PICO format (from the initials: Patient, Intervention, Control and Outcome)
