Although earlier research may suggest otherwise, traditional new research suggests.
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Researchers used what they described as “a novel data linkage” comparing 30-day readmission rates after hospitalization for three major conditions in the Hospital Readmissions Reduction Program for patients using traditional Medicare versus Medicare Advantage. Those conditions included acute MI, heart failure, and pneumonia.
“Our results contrast with those of previous studies that have reported lower or statistically similar readmission rates for Medicare Advantage beneficiaries,” Orestis A. Panagiotou, MD, of Brown University, Providence, R.I., and colleagues wrote in a research report published in Annals of Internal Medicine.
In this retrospective cohort study, the researchers linked data from 2011 to 2014 from the Medicare Provider Analysis and Review (MedPAR) file to the Healthcare Effectiveness Data and Information Set (HEDIS).
The novel linkage found that HEDIS data underreported hospital admissions for acute MI, heart failure, and pneumonia, the researchers stated. “Plans incorrectly excluded hospitalizations that should have qualified for the readmission measure, and readmission rates were substantially higher among incorrectly excluded hospitalizations.”
Despite this, in analyses using the linkage of HEDIS and MedPAR, “Medicare Advantage beneficiaries had higher 30-day risk-adjusted readmission rates after [acute MI, heart failure, and pneumonia] than did traditional Medicare beneficiaries,” the investigators noted.
Patients in Medicare Advantage had lower unadjusted readmission rates compared with those in traditional Medicare (16.6% vs. 17.1% for acute MI; 21.4% vs. 21.7% for heart failure; and 16.3% vs. 16.4% for pneumonia). After standardization, Medicare Advantage patients had higher readmission rates, compared with those in traditional Medicare (17.2% vs. 16.9% for acute MI; 21.7% vs. 21.4% for heart failure; and 16.5% vs. 16.0% for pneumonia).
The study authors added that, while unadjusted readmission rates were higher for traditional Medicare beneficiaries, “the direction of the difference reversed after standardization. This occurred because Medicare Advantage beneficiaries have, on average, a lower expected readmission risk [that is, they are ‘healthier’].” Prior studies have documented that Medicare Advantage plans enroll beneficiaries with fewer comorbid conditions and that high-cost beneficiaries switch out of Medicare Advantage and into traditional Medicare.
The researchers suggested four reasons for the differences between the results in this study versus others that compared patients using Medicare with those using Medicare Advantage. These were that the new study included a more comprehensive data set, analyses with comorbid conditions “from a well-validated model applied by CMS [Centers for Medicare & Medicaid Services],” national data focused on three conditions included in the Hospital Readmissions Reduction Program, and patients discharged to places other than skilled nursing facilities and inpatient rehabilitation facilities.
Authors of an accompanying editorial called for caution to be used in interpreting Medicare Advantage enrollment as causing an increased readmission risk.
“[The] results are sensitive to adjustment for case mix,” wrote Peter Huckfeldt, PhD, of the University of Minnesota, Minneapolis, and Neeraj Sood, PhD, of the University of Southern California, Los Angeles, in the editorial published in Annals of Internal Medicine (2019 June 25. doi:10.7326/M19-1599) “Using diagnosis codes on hospital claims for case-mix adjustments may be increasingly perilous. ... To our knowledge, there is no recent evidence comparing the intensity of diagnostic coding between clinically similar [traditional Medicare] and [Medicare Advantage] hospital admissions, but if [traditional Medicare] enrollees were coded more intensively than [Medicare Advantage] enrollees, this could lead to [traditional Medicare] enrollees having lower risk-adjusted readmission rares due to coding practices.”
The editorialists added that using a cross-sectional comparison of Medicare Advantage and traditional Medicare patients is concerning because a “key challenge in estimating the effect of [Medicare Advantage] is that enrollment is voluntary,” which can lead to a number of analytical concerns.
The researchers concluded that their findings “are concerning because CMS uses HEDIS performance to construct composite quality ratings and assign payment bonuses to Medicare Advantage plans.
“Our study suggests a need for improved monitoring of the accuracy of HEDIS data,” they noted.
The National Institute on Aging provided the primary funding for this study. A number of the authors received grants from the National Institutes of Health during the conduct of the study. No other relevant disclosures were reported.
SOURCE: Panagiotou OA et al. Ann Intern Med. 2019 Jun 25. doi: 10.7326/M18-1795.