Question

n a randomized trial of two drugs to treat depression (drug A and drug B), depressive symptoms decreased significantly in patients on drug A (p<.001) but not in patients on drug B (p>.05). It follows that: Drug A is superior to drug B. Drug A and drug B are equally effective. Drug B is superior to drug A. None of the above

Answer 1

Drug A: p<.001 means that chance alone would produce such a result less than once in every 1000 studies.
Drug B: p>.05 means that chance alone would produce such a result more than 5 times in every 100 studies.
A p-value greater than 0.05 is taken to mean that the observed difference might have occurred by chance. Therefore the null hypothesis (that there is no difference) is not rejected.
In such a case it is not possible to demonstrate a difference between the drugs.

Answer 2

None of the above

Answer 3

That is the correct choice.