Ray is absolutely right about how things started, and Pediatricians in general are the most liberal group of physicians that I have met from the perspective of not believing in individual rights or gun rights.
The gov't is getting more and more control of health care in this country, whether people realize it or not (this is not a new thing, but rather hidden well previously from the average health care consumer). It is not a far stretch for the federal government to coopt suggestions from left leaning physician groups and bureaucrats and include them as required reporting for providers, and as such a required part of electronic health records for "meaningful use".
Once those suggestions become required reporting for physicians, then the government has access to all of that information in audits, but I don't believe they can seek out information which is individually identified to you at this point if you are privately insured. But if the gov't pays your health care bills, then as the payor, they will be able to access everything about you directly and which is directly identified as being your info, regardless of what system your doctor uses. When you are seen at a clinic, you sign paperwork authorizing medical information to be released to the payor of your medical bills to ensure proper billing/payment...and that is all without the gov't even having to use the NSA to acccess some big health insurance company's records on the cloud, and without the state sharing info with the feds about what you have purchased (here in WA the state tracks your hangun purchases, and now apparently all purchases pending any court challenges).
So, the bottom line is. If you want privacy, then don't have the gov't pay your health care bills, vote against all progressives or people that are for more state control and against personal responsibility, and don't give any information which you don't want to get out there.