Hospitals never get into bed with a physician without finding some way to screw him out of $$$. Hospitals have one goal: to make money for the hospital. It has nothing to do with providing services to those in need nor does quality of care matter to the hospital- as long as you are generating revenue for them. With respect to payor class mix: hospital based practices have a large percentage of medicaid (virtually non-pay) and self pay (non-pay) while they skim 2/3 of your income on all Medicare cases due to the site of service differential. Some major private insurances such as Anthem/Wellpoint now pay the physician medicare rates with a site of service differential, therefore you get screwed doing these cases in a hospital also. You are locked into whatever insurances and social programs the hospitals accept and cannot independently negotiate rates nor elect to opt out of insurances/social programs with inadequate reimbursement. Add on the fact that some hospital administrators are so sleazy they hire CRNAs to do pain medicine, the infinite calls and BS admissions of clearly chronic pain patients through the ER with no change in daily pain status, the calls at night from your obligatory medicaid population about why they need more narcotics, and the hassles with inept hospital credentialing committees that use 5 year old "White papers" to decide who is privileged for what procedures and you will soon discover financially it is in your best interest to divorce yourself as soon as possible from the money sucking hospitals. My strong preference is when possible, remain independent from hospitals at all costs. If you must join a group, then go to the local neurosurgeon/OSS and ask to join them. If there are none, then if there is a dominant IM group in town, try to rent space from them for your office....
Hospitals are rarely your friends, and in many cases can turn out to be the enemy when they align themselves with untrained or poorly trained individuals to compete against your private practice. They simply do not care...it is ALL about $$$$ for them.