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Are Medicare Advantage Patients Less Likely to have a Readmission? (Text Version)

Slide presentation from the AHRQ 2010 conference.

On September 27, 2010, Bernard Friedman made this presentation at the 2010 Annual Conference. Select to access the PowerPoint® presentation (635 KB). 

Slide 1

Are Medicare Advantage Patients Less Likely to have a Readmission?

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

Slide 2



  • 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.

Slide 3

Data Preparation

Data Preparation

  • 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)

Slide 4

Data Preparation

Data Preparation

  • Dependent Variables: at least one readmission within 30 days, 90 days
  • Notes:
    • 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

Slide 5

Initial Comparisons

Initial comparisons

  • 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:
    • Younger
    • 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.

Slide 6

Problem: Self-selection

Problem: Self-Selection

  • 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,

Slide 7

Results of Tests

Results of Tests

  • Preliminary
  • 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.
Current as of December 2010
Internet Citation: Are Medicare Advantage Patients Less Likely to have a Readmission? (Text Version). December 2010. Agency for Healthcare Research and Quality, Rockville, MD.


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