Are Medicare Advantage Patients Less Likely to have a Readmission? (Text Version)
On September 27, 2010, Bernard Friedman made this presentation at the 2010 Annual Conference. Select to access the PowerPoint® presentation (635 KB).
Are Medicare Advantage Patients Less Likely to have a Readmission?
Bernard Friedman, PhD
Joanna Jiang, PhD
John Bott MSSW, MBA
Claudia Steiner MD, MPH
AHRQ Conference, 2010
- Hypothesis: the Advantage plans have both the motive (capitated revenue) and the means to reduce readmissions in comparison to FFS.
- Use 2006 data.
- 14 HCUP states distinguish FFS and MA payer on discharge summary.
- 5 states in HCUP also had reliable person identifiers. AZ, CA, FL, Mass, TN.
- NY could now also be used.
- Selecting Cases:
- Elderly Medicare beneficiary patient from urban CBSAs
- Initial admission Jan-Sept of 2006
- Match to Linkage file (work-saving tool, uses no actual dates, releasable => replicable study, protecting identity)
- Use primary and secondary payer
- Discharged alive from initial admission
- Screening out re-hospitalizations:
- Same day transfer (using Linkage File)
- Re-hospitalization says transferred in from another hospital
- Pregnancy or maternity-related
- Trauma-related principal condition (CCS 225-236)
- Dependent Variables: at least one readmission within 30 days, 90 days
- Each person enters only once, from initial admission.
- Not addressing the "burden of readmissions", i.e., multiple readmissions within any fixed period, overlapping episodes for a person during the year.
- ED revisits not included
- 266K MA initial discharges, 868K initial FFS discharges
- 30 day readmission rate: 13.7% vs. 14.4%
- 90 day readmission rate: 23.8% vs. 26.2%
- However, Medicare Advantage patients tend to be:
- Less severely ill even when hospitalized
- Less likely to be Medicaid enrolled as well
- Less likely to have a major operative procedure.
- For more detailed comparison over 13 states, refer to Stat Brief #66.
- Other work: AHIP study of CA and NV found a lower rate of preventable admissions for Advantage enrollees.
- Instrumental Variable approach:
- What can we measure that could affect enrollment in an Advantage plan rather than FFS?
- Instrument should not itself affect the likelihood of readmission.
- R = f (M, X)
- M= g(Z)
- Z affects M but not R (standard tests for the performance of Z set)
- Z: CBSA characteristics. HMO penetration among younger insured, number of competing hospitals, available medical specialists,
Results of Tests
- Controlling for self-selection, Medicare Advantage patients had a 9% higher likelihood of readmission in 30 days.
- Tests of the Instruments are passed
- Caveats: high users, ED visits
- Looking for a Reconciliation:
- Enrollees do not have data to compare readmission rates when choosing a plan.
- Health Plans do not have adequate measures of risk-adjusted readmission rates for quality improvement efforts.
- Saving money on readmissions is not the only way to save.