I have mentioned before that our medical system is shockingly primitive. Our respect and trust in doctors and medicine is, in many cases, based more on superstition and hope than hard evidence.
Here is an article that discusses some of the evidence. A new study has shown that, after properly controlling for conditions in the lives of people, health insurance does nothing to your chances of dying. Health insurance should be seen as a symptom of being a healthy person with a good job. It is correlated with good health, but it does nothing to actually prevent you form dying.
An earlier experiment, run by the Rand corporation, was the only actual experiment anyone has done on the effects of health insurance. It found that more generous health insurance made people consume more health care, but did nothing to make them healthier.
We also observe that there is no change in population mortality rates when people reach age 65 and get Medicare. There are millions of people who lack insurance but gain it at age 65. Medicare is at least as generous as most private plans, so even the people who had insurance before end up getting more if it. If health insurance were saving lives, then people who are 66 should die less often then people who are 64. It is true that death rates increase as people get older, but if Medicare did anything to save lives a statistical analysis would show some kind of change.
And yet, we see zero effect on mortality rates as a result of people getting enrolled in Medicare. The conclusion from the evidence is that it does nothing to save lives. The only thing it does is make people feel better. They value the attention of the medical professionals, even though nothing is being changed that can be detected by any study.