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Role of Patient Sorting in Avoidable Hospital Stays in Medicare Advantage vs Traditional Medicare
Jianhui Frank Xu1, Kelly E Anderson2, Angela Liu1
1Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland.
Importance:
Unlike traditional Medicare (TM), Medicare Advantage (MA) plans limit in-network care to a specific network of Medicare clinicians. MA plans thus play a role in sorting patients to a subset of clinicians. It is unknown whether the performance of physicians who treat MA and TM beneficiaries is different.
Objective:
To examine whether avoidable hospital stay differences between MA and TM can be explained by the primary care clinicians who treat MA and TM beneficiaries.
Design, Setting, And Participants:
This was a cross-sectional study of a nationally representative sample of MA and TM beneficiaries in 2019 with any of 5 chronic ambulatory care-sensitive conditions (ACSCs). The relative risk (RR) of avoidable hospital stays in MA compared with TM was estimated with inverse probability of treatment-weighted Poisson regression, both without and with clinician fixed effects. The degree to which the estimated MA vs TM difference could be explained by patient sorting was calculated by comparing the 2 RR estimates. Data were analyzed between February 2022 and April 2023.
Exposure:
Enrollment in MA.
Main Outcome And Measures:
Whether a beneficiary had avoidable hospital stays in 2019 due to any of the ACSCs. Avoidable hospital stays included both hospitalizations and observation stays.
Results:
The study sample comprised 1 323 481 MA beneficiaries (mean [SD] age, 75.4 [7.0] years; 56.9% women; 69.3% White) and 1 965 863 TM beneficiaries (mean [SD] age, 75.9 [7.4] years; 57.1% women; 82.5% White). When controlling for the primary care clinician, the RR of avoidable hospital stays in MA vs TM changed by 2.6 percentage points (95% CI, 1.72-3.50; P < .001), suggesting that compared with TM beneficiaries, MA beneficiaries saw clinicians with lower rates of avoidable hospital stays. This effect size was statistically significant to explain the 2% lower rate of avoidable hospital stays in MA than in TM.
Conclusions And Relevance:
In this cross-sectional study of MA and TM beneficiaries, the lower rate of avoidable hospital stays among MA beneficiaries than TM beneficiaries was attributable to MA beneficiaries visiting clinicians with lower rates of avoidable hospital stays. The patient sorting that occurs in MA plays a critical role in the lower rates of avoidable hospital stays compared with TM.
Insights
Medicare Advantage (MA) plans lead to fewer avoidable hospital stays because beneficiaries are directed to clinicians with better performance. This patient sorting within MA networks significantly contributes to the observed differences compared to traditional Medicare (TM).
Area of Science:
- Health Services Research
- Health Economics
- Clinical Quality Measurement
Background:
- Traditional Medicare (TM) beneficiaries receive care from a broad network of clinicians.
- Medicare Advantage (MA) plans restrict beneficiaries to a specific network, influencing patient-clinician relationships.
- The comparative performance of clinicians treating MA versus TM beneficiaries is not well understood.
Purpose of the Study:
- To investigate if differences in avoidable hospital stays between MA and TM beneficiaries can be attributed to the primary care clinicians involved.
- To quantify the impact of patient sorting by MA plans on avoidable hospitalizations.
Main Methods:
- Cross-sectional study utilizing a nationally representative sample of MA and TM beneficiaries in 2019.
- Analysis focused on patients with one of five chronic ambulatory care-sensitive conditions (ACSCs).
- Inverse probability of treatment-weighted Poisson regression was used to estimate relative risks (RR) of avoidable hospital stays, with and without clinician fixed effects.
Main Results:
- A total of 1,323,481 MA and 1,965,863 TM beneficiaries were included.
- Controlling for primary care clinicians reduced the RR of avoidable hospital stays in MA vs TM by 2.6 percentage points (P < .001).
- This indicates MA beneficiaries were treated by clinicians with demonstrably lower rates of avoidable hospital stays, explaining a 2% lower overall rate.
Conclusions:
- Lower rates of avoidable hospital stays in MA compared to TM are significantly influenced by patient sorting to higher-performing clinicians.
- The network design of MA plans plays a crucial role in directing patients to clinicians associated with better outcomes.
- These findings highlight the impact of managed care network structures on healthcare utilization and quality.
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