Randomized controlled trials are gaining traction in the health care policy realm. Long used for studying whether certain drugs work, RCTs are now being applied to the questions of what health care delivery systems are the most effective and efficient. Some surprising results: In a study in Oregon, those with insurance actually visited the emergency room more (they also seemed to have better health outcomes). Another study found that those patients who received palliative care not only had higher quality of life but actually lived longer than the control group. RCTs aren't perfect, but I think they may be a key part of any investigation of health system. Health care is too complicated and too important to be governed by "gut instinct" alone.