Quality assessment of studies
S-N and A-M used the criteria provided by the Cochrane Collaborations tool for assessment of quality and risk of bias in selected studies[13]. Methodological features applied for assessment were: (a) random sequence generation; (b) allocation concealment; (c) blinding of participants and personnel; (d) blinding of outcome assessment; (e) incomplete outcome data, (f) selective outcome reporting (reporting bias), and (g) other potential sources of bias. According to the recommendations of the Cochrane Handbook, studies were assessed to have a high risk, low risk or unclear. Poorly reported articles were labeled an item as “unclear”, suggesting an unclear or unknown risk of bias.