Trials: Nobody's Perfect, Randomized Controlled or Not

Randomized controlled trials are the gold standard of clinical research, and for good reason. They are "at the top of the evidence hierarchy. . . . They give us the most robust evidence," Caroline Sabin of University College London told the audience at a recent workshop on clinical trial design.

Both due to the randomization itself, and due to the presence of a control group, such trials give "very robust evidence" about an intervention's merits, she said.

But it's not always possible to do a randomized controlled trial.