Comparative effectiveness is when you compare the effectiveness of medical treatments. Surprisingly little of this is done in many quickly evolving fields.
For example, as Businessweek reports, medical researchers recently found that in patients with stable heart disease, angioplasty works no better than drugs. Angioplasty is putting a stent into an artery to keep it open. In other words, angioplasty should be limited to those with severe heart attacks or severe chest pain (aka angina).
Comparative effectiveness is needed because people and companies profit off procedures that don't improve health.
In addition, Dr. Albert G. Mulley, an associate professor of medicine and health-care policy at Massachusetts General Hospital, sees angioplasty as "the poster child for supply-induced demand." Once hospitals have made big investments in the catheterization laboratories, where the procedures are done, they have every incentive to use them as much as possible. Plus, patients also have bought into the argument that clogged arteries should be propped open. "There is a huge demand from patients for quick dramatic fixes," says Mulley.
It's not that we're going towards socialism, as some charge, but we do want some mechanism to help people make money off the stuff that improves health, rather than the stuff that doesn't do better than cheaper alternatives.