Which of the following sentences is correctly punctuated?

We conducted a randomized placebo-controlled trial.

OR

We conducted a randomized, placebo-controlled trial.

ANSWER:

We conducted a randomized placebo-controlled trial.

When fewer than 3 modifiers are used, avoid adding a comma if the modifiers and the noun are read as one entity, such as randomized placebo-controlled trial.—Laura King, ELS