[etendue]

It's of course very complex, but three things not always mentioned: Dealing with the insurance companies and their Byzantine billing practices requires hiring additional staff to specifically deal with billing issues, with that cost passed to the patient. Electronic medical records slow down physicians, (fewer patients seen requires billing more for those you do see) and at least the ones I've experienced end up being more expensive than paper records. The insurance companies also are very slow in reimbursements to physicians (sometimes several months behind) which requires billing more to help compensate for the uncertainty.

Also, insurance frequently doesn't reimburse enough to cover the actual cost of a procedure, e.g., vaccines.