Misleading description

No evidence

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. This is not right. We cannot be sure that there is “no difference”, or whether one treatment 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”.