Medical studies are immediately ended when someone dies in a group. So it is impossible for a study to determine a danger of death because the study will always be halted upon anyone's death. It's rather atrocious, but that's the way research works on willing human subjects.
In general, what you claim would seem both surprising and impractical to me. There are many studies on very seriously ill groups, where the death of a large portion of participants is expected.
Even when walking around eating ice cream. Death is everywhere. Capitalistic america hides it in hospitals and hospices. Our culture needs more visibility into the process of life to death. Instead, we have to learn it by watching one of our loved ones die, and hell, we don't even know if they are being treated right -- because no one ever tells us how death should go. It's all siloed. Fuck America.
