Table 3. Cochrane risk of bias tool of the included trials.

Trial	Random sequence generation	Allocation concealment	Blinding	Incomplete outcome data	Selective outcome reporting	Other potential sources of bias
MA 17	Low	High	Unclear	Low	Low	Low
ABCSG 6a	Low	High	Low	Low	Low	Unclear
NSABP-33	Low	High	Low	Low	Low	Low
NSABP-42	Low	Unclear	Low	Low	Low	Low
DATA	Low	Low	Low	Low	Low	Low
LATER	Low	High	Unclear	High	Low	High
IDEAL	Low	High	Low	Low	Low	Unclear
MA 17R	Low	High	Unclear	Low	Low	Low