Study quality Random sequence Allocation concealment Blinding participants Blinding outcome Incomplete outcome Selective reporting Turner()(?)() (X) Walker()(?)(X) ()(X) Heisler() (X)(?)()(X) Dale(?)(X) (?) (X) Samuel()(X) (?)()(?) Parry() (X)(?)()(?) Batik(X)(?)(X)(?) Carroll(?) (X)(?) Young() (?) ()(?) Keyserling()(X) ()(X)