“…In regard to randomization, there was no mention of random sequence generation in any study; while 33% of the studies mentioned random allocation of samples. 12,15,16,18,19,21,23,24,27,28,32,34,53,54,58,[62][63][64]71,72,74,75 Where only abstracts could be retrieved, the risk of selective reporting was unclear. 39,40,43,44,67 However, no such bias could be detected in the full-text articles.…”