You have probably never given this issue much thought, but there are in fact several benefits from taking part in a large clinical trial. Many people don't like the idea of being a guinea pig, but in the sort of trials we are talking about this is not really an issue. The large trials now in progress are all using medications that are known to lower blood pressure with few side effects, and the only 'experimental' aspect of them is the question they are designed to answer: whether one form of treatment for high blood pressure is better than another at preventing strokes and heart attacks. Since at the present time there is no good evidence that any one type of medication is superior to any other in this regard, you're not putting yourself at much risk. Indeed, since the medications being tested are all approved and widely used, there is a good chance that your doctor might prescribe you one of the study drugs without your being in any trial.

Actually, the chances are that you will get better care if you enroll in a trial. You will be evaluated in a very systematic way, have regular checkups, and the doctors and nurses conducting the trial will go to great lengths to keep you happy. It's very important to them that you stay in the trial, even though you are, of course, free to leave it whenever you want. You need not be concerned that if the chosen medication does not appear to be working, you have to stick with it: there will be built-in safeguards to ensure that your blood pressure is adequately controlled, if necessary by adding another medication.

Your treatment will also be free. This will include the costs of the medications and may also include the costs of visits and tests (any test that's not routine will certainly be covered).