I don’t know, but I can offer one strange symptom.
A friend showed me the receipt from his HMO. He had gone for a test recommended when one passes age 50, and received the statement advising his copay. The bill from the hospital was $1200. The HMO allowed only $200, and so they paid the hospital $180, leaving my friend with a $20 copay. What’s wrong with this picture? If someone with no insurance received the same test, they would be stuck with the original $1200 bill. Worse, they might not get tested at all, and potentially face a life threatening illness that could have been avoided.
I’m used to seeing HMOs discount a $150 doctor visit to $120 or other bills reduced by 10-30%, but this just seemed to be over the top. I don’t have the answers on this issue, I just recognize the system is broken.