Academic health systems management: the rationale behind capitated contracts.
OBJECTIVE
To determine why hospitals enter into "capitated" contracts, which often generate accounting losses. The authors' hypothesis is that hospitals coordinate contracts to keep beds full and that in principal, capitated contracts reflect sound capacity management.


BACKGROUND
In high-overhead industries, different consumers pay different prices for similar services (e.g., full-fare vs. advanced-purchase plane tickets, full tuition vs. financial aid). Some consumers gain access by paying less than total cost. Hospitals, like other high-overhead business enterprises, must optimize the use of their capacity, amortizing overhead over as many patients as possible. This necessity for enhanced throughput forces hospitals and health systems to discount empty beds, sometimes to the point where they incur accounting losses serving some payors.


METHODS
The authors analyzed the cost accounting system at their university teaching hospital to compare hospital and intensive care unit (ICU) lengths of stay (LOS), variable direct costs (VDC), overhead of capitated patients, and reimbursement versus other payors for all hospital discharges (n = 29,036) in fiscal year 1998. The data were analyzed by diagnosis-related groups (DRGs), length of stay (LOS), insurance carrier, proximity to hospital, and discharge disposition. Patients were then distinguished across payor categories based on their resource utilization, proximity to the hospital, DRG, LOS, and discharge status.


RESULTS
The mean cost for capitated patients was $4,887, less than half of the mean cost of $10,394 for the entire hospitalized population. The mean capitated reimbursement was $928/day, exceeding the mean daily VDC of $616 but not the total cost of $1,445/day. Moreover, the mean total cost per patient day of treating a capitated patient was $400 less than the mean total cost per day for noncapitated patients. The hospital's capitated health maintenance organization (HMO) patients made up 16. 0% of the total admissions but only 9.4% of the total patient days. Both the mean LOS of 3.4 days and the mean ICU LOS of 0.3 days were significantly different from the overall values of 5.8 days and 1 day, respectively, for the noncapitated population. For patients classified with a DRG with complication who traveled from more than 60 miles away, the mean LOS was 10.7 days and the mean total cost was $21,658. This is in contrast to all patients who traveled greater than 60 miles, who had an LOS of 7.2 days and a mean total cost of $12,569.


CONCLUSIONS
The capitated payor directed the bulk of its subscribers to one hospital (other payors transferred their sicker patients). This was reflected in the capitated group's lower costs and LOS. This stable stream of relatively low-acuity patients enhanced capacity utilization. For capitated patients, the hospital still benefits by recovering the incremental cost (VDC) of treating these patients, and only a portion of the assigned overhead. Thus, in the short run, capitated patients provide a positive economic benefit. Other payors' higher-acuity patients arrive more randomly, place greater strains on capacity, and generate higher overhead costs. This results in differential reimbursement to cover this incremental overhead. Having a portfolio of contracts allows the hospital to optimize capacity both in terms of patient flows and acuity. One risk of operating near capacity is that capitated patients could displace other higher-paying patients.
Taheri
P A
PA
Division of Trauma, Burn, and Emergency Surgery, University of Michigan Health System, Ann Arbor, MI 48109-0033, USA. taheri@umich.edu
Butz
D A
DA
Greenfield
L J
LJ
D002204:Capitation Fee; D003361:Cost Allocation; D003953:Diagnosis-Related Groups; D006279:Health Maintenance Organizations / Q000191:economics; D006301:Health Services Needs and Demand / Q000191:economics; D006764:Hospitals, Community / Q000191:economics; D006785:Hospitals, University / Q000191:economics*; D006801:Humans; D007902:Length of Stay / Q000191:economics; D008824:Michigan; D012189:Retrospective Studies