Look out for a “lack of evidence” being described as evidence of “no difference”.
Sometimes, when the difference in what happens (outcomes) between treatment comparison groups is uncertain, people say there is “no evidence” that one treatment is better or worse than the other. This lack of evidence is often taken to mean that there is “no difference” between the treatments, which is incorrect. If there is a lack of evidence, we cannot be sure that there is no important difference, or whether one intervention is better or worse than the other.
REMEMBER: Don’t confuse “no evidence” or “a lack of evidence” with “no difference” or “no effect.” And don’t be fooled if someone says there is “no difference” or “no effect”.