Comparative research studies in the past haven't always had incredible results

Comparative effectiveness research is all the rage right now, and everyone is talking about how much we need it. But are we forgetting what happened with perhaps the largest comparative effectiveness study ever undertaken?

Started in 1994, the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (Allhat) was launched. It was ambitious, with 42,000 people eventually participating and four drugs being compared. And its results were surprising: the least expensive option out of the four drugs studied, a diuretic called chlorthalidone, had the best results.

Perhaps even more surprising to the study's researchers, though, was the lack of dramatic results from this massive study. Pharmaceutical companies argued that their drugs had been at a disadvantage in the test and generally worked to confuse the results in doctors' minds. The end result was that only 5 to 10 percent more patients were prescribed diuretics.

And over the course of the study from 1994 to 2002, when the results were released, pharmaceutical companies continued their development cycles and came out with new drugs that hadn't been included in the study.

Hopefully when policy experts and legislators are considering comparative effectiveness research, they will look to the past and try to resolve some of the potential problems that we've already had demonstrated to us.

To learn more about the study and its results:
- read this New York Times piece