Big studies don't always change doctors' habits

One of the biggest debates looming in 2009 will be over the role of comparative effectiveness trials to evaluate the real worth of new therapies. But even if the new trials are mounted, will fresh data help rein in the use of more expensive therapies?

The New York Times' Andrew Pollack outlines how solid evidence that diuretics can be more effective than hypertension drugs has failed to lead to a major change in the way that physicians treat their patients.

The use of diuretics among hypertensive patients jumped from about 30 to 35 percent to 40 percent after a $130 million study provided ample data on their efficacy. But then use stayed at that level, even as the use of new hypertension drugs has surged.

A debate over the trial design helped to blunt the impact of the government funded study, but observers also note that it is hard to change the way that doctors practice medicine. And others add that drug companies were able to significantly increase spending on advertising on their new therapies.

- read the article in the New York Times