But then a randomized trial showed it was a bad idea.

It is the patient's choice to be in a randomized trial.

"The point that we want to get across was the value in doing randomized trials," he said.

"Has there been a randomized trial of screening for this?"

The results from two of the largest randomized trials have now been published.

Even if a particular study is a randomized trial, it may not provide strong evidence for the effectiveness of disease management.

Results from several large-scale randomized trials were published in early 2009.

To continue with randomized trials, he goes on, "means 15 percent of patients would have to die to prove a point."

Any of the treatment groups in a randomized trial.

However, the two groups were not necessarily comparable, as it was no longer a randomized trial.

Now consider the design of a randomized trial with an all death endpoint.

No prospective or randomized trials document the value of this approach.

The use of randomized trials to inform education policy.

There is no single institution that will enroll enough patients to perform a randomized trial.

Only a properly designed randomized trial can demonstrate whether an important benefit exists.

However, a prospective, randomized trial has not been performed.

This group also published recommendations for authors reporting randomized trials.

A randomized trial of teacher development in elementary science: First-year achievement effects.

"It wasn't a huge study but it was the only randomized trial there is," she said.

Because randomized trials provide clear, objective evidence on "what works", policy makers often take only those studies into consideration.

A recent randomized trial was discontinued because it failed to demonstrate any benefit.

In the last decade, there has been a steady shift by medical investigators to such randomized trials.

No randomized trials have been conducted on treatment of oral warts.

Several randomized trials with cancer patients have suggested that group support interventions benefit survival.

But neither study is definitive, because neither was a randomized trial.