text: The quality of concealment allocation was interpreted according to Gibson and Waddell [19] in 3 grades: A, clearly yes is some form of centralized randomization scheme or assignment system; B, unclear, assignment envelopes, a ‚Äò‚Äòlist‚Äô‚Äô or ‚Äò‚Äòtable‚Äô‚Äô, evidence of possible randomization failure such as markedly unequal control and trial groups, or trials stated to be random but with no description; C, clearly no, alternation, case numbers, dates of birth, or any other such approach, allocation procedures that were transparent before assignment.