Likelihood of hospital readmission in Medicare Advantage and Fee-For-Service within same hospital.

Objective: To assess the extent to which all-cause 30-day readmission rate varies by Medicare program within the same hospitals.

Study Design: We used conditional logistic regression clustered by hospital and generalized estimating equations to compare the odds of unplanned all-cause 30-day readmission between Medicare Fee-for-Service (FFS) and Medicare Advantage (MA).

Data Collection: Wisconsin Health Information Organization collects claims data from various payers including private insurance, Medicare, and Medicaid, twice a year.

Principal Findings: For 62 of 66 hospitals, hospital-level readmission rates for MA were lower than those for Medicare FFS. The odds of 30-day readmission in MA were 0.92 times lower than Medicare FFS within the same hospital (odds ratio, 0.93; 95 percent confidence interval, 0.89-0.98). The adjusted overall readmission rates of Medicare FFS and MA were 14.9 percent and 11.9 percent, respectively.

Conclusion: These findings provide additional evidence of potential variations in readmission risk by payer and support the need for improved monitoring systems in hospitals that incorporate payer-specific data. Further research is needed to delineate specific care delivery factors that contribute to differential readmission risk by payer source.