Randomized controlled trials: a misnomer?

“Randomized controlled trial” strikes me as a misnomer, because randomization is a surrogate for true control. There may be an argument that randomization has the same effect as controlling. But even if it does have the same effect (which is doubtful), randomization clearly does not involve literally controlling the potentially relevant differences between the control case and the test case. In fact rather the opposite.

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One thought on “Randomized controlled trials: a misnomer?

  1. Alex, I think that randomization is meant to reduce selection bias, in that the researcher has no control over who enters which arm of a trial. It is not a guarantee that the arms will be exactly alike, although a large number of participants should reduce the known and unknown differences between the cases and controls. After randomization, researchers should normally test the arms on known variables to see if there are important differences, particularly on variables known to affect the outcome. Even if the arms are perfectly alike at the moment of randomization, the mix of variables in one or every arm may change with differential drop-out during follow-up.

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