There are different figures, partly as a result of how this question is studied. The Mayo Clinic did a famous study on people who sought a second opinion, and t

There are different figures, partly as a result of how this question is studied. The Mayo Clinic did a famous study on people who sought a second opinion, and they found that something like 12% of people seeking that second opinion were correctly diagnosed. Obviously this isn't a fair sample since this is not only people seeking a second opinion, but one from a prestigious source. This narrative review discusses the issue from a global perspective, concluding that most people will experience at least one misdiagnosis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5502242/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5502242/ Article on Mayo study, with link to study: https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-researchers-demonstrate-value-of-second-opinions/ https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-re...