You may be able to change a medical test if it hasn't been read by anyone. The instant the test has been read by a lab worker, the results are in the data stream. Say blood is drawn and you want the test to read a certain way, you can use focused Intent to influence how the test comes out. But that won't change the medical condition behind the test. It will just make the test false. If you want to influence health, then your Intent has to be on that before the diagnosis is made. Otherwise there is very little randomness to work with.
For a thorough explanation of how this works watch:
US Space and Rocket Center (Part 1 of 3)
https://www.youtube.com/watch?v=IcxeEaO ... bCRsMi_IM