I was also in the medical field. However, I think we can't draw conclusions based on a selected group already -- e.g. people with health care backgrounds are probably more likely to seek out ME/CFS conferences and forums than your average person so it might LOOK like more health care folks are affected but to really answer the question, you'd need to do a larger/ different type of study. It's also why ME/CFS was initially called "yuppie" flu -- I suspect that people with enough knowledge, money, gumption, etc. to find out their diagnosis and resist being labelled as "depressed"/ "lazy"/ "psychosomatic" were probably younger, well-educated, professionals. There are poor less well-educated folks with this but they might not have the same knowledge, access to care, etc.