Unfortunately, as we are all aware, post-polio syndrome falls into this category. Since many of us have been or will in the future be asked to participate in research, I think it is wise for us to consider a few questions and options. Of course, the first consideration is what the physician conducting the research hopes to learn. You would also want to know if there is a risk to you by participating in the research and if there would be any charges to you or your insurance company.
Most research is funded totally by either a grant or the institution conducting the research.
All research plans must be reviewed by that institution's review board for the use of human subjects, so that they can evaluate the ethical use and the amount of risk to the prospective participant. These results should be available to you if you inquire. You will also want to know how many visits the research will require and evaluate your personal situation to see if this is a possibility for you. Some research programs require only yearly evaluations. Others may require weekly or even more frequent visits.