Risk of Bias
According to the Revised Cochrane risk-of-bias tool for randomized trials (RoB 2), regarding the randomized controlled trials included, only some concern was found in some studies. No study reported another risk of bias for our outcome variables (Figure 2).
Regarding the non-RCT studies, according to the Newcastle-Ottawa Scale (NOS) for Assessing the Quality of Nonrandomized Studies in Meta-Analysis, no high risk of bias was found for any study, especially for the parameters relating to outcomes (Table 1).
Among the studies initially included in the ”corticosteroid group” (Cort), 5 used dexamethasone, 5 used betamethasone, one used methylprednisolone, and one used deflazacort. In 7 studies corticosteroids were administered post-operatively, in 3 studies pre-operatively, in one study both pre- and post-operatively, and in one study they were administered intra- and post-operatively. Corticosteroids were administered orally (7 studies), intramuscularly (3 studies), intravenously (3 studies), and both orally and intramuscularly (one study).