Abstract
Objectives:
To compare enrollment rates in Medicare Advantage (MA) among people with disabilities (PWD) and individuals with End Stage Renal Disease (ESRD) in the US (50 states and DC) and Puerto Rico (PR).
Study Design:
This observational study utilizes repeated cross-sectional data from the Master Beneficiary Summary File from 2008 – 2022.
Methods:
The sample included beneficiaries who had continuous Medicare enrollment during the corresponding calendar year and were alive at the end of March 31 in the following year. Partial-year MA enrollment was defined as having between one and twelve months of MA coverage. Full-year MA enrollment was defined as having continuous MA coverage for all twelve months. We calculated the percentage of enrollees in MA based on their entitlement (age, disability, and ESRD). Standardized differences were calculated to compare characteristics of US and PR enrollees in 2022.
Results:
Between 2008 and 2022, our study included 757,245,942 person-years from the US and 10,298,906 person-years from PR. In 2022, Medicare beneficiaries in PR exhibited a higher partial-year MA enrollment rate – nearly double that of the US (84% vs. 48%; [d = 0.837 (95% confidence interval, 0.835 – 0.839)). In addition, in the US, the difference between partial-year and full-year MA enrollment rates was 5.7% for PWD and 9.1% for ESRD enrollees. In PR, the differences were 2.7% for PWD and 10.0% for ESRD enrollees.
Conclusions:
Discrepancies between partial-year and full-year MA enrollment persisted among PWD and ESRD subpopulations, highlighting potential differences in coverage and access to care for these groups.
Keywords: Health plan selection, Medicare Advantage, vulnerable populations, Socioeconomic factors
Precis:
Medicare Advantage enrollment has increased in the US and Puerto Rico, with a dramatic growth among Puerto Rico beneficiaries with End Stage Renal Disease
Introduction
For a few decades Medicare Advantage (MA) plans have provided coverage for people aged 65 and older, and younger people with disabilities (PWD). 1 In January 1, 2021, the 21st Century Cures Act expanded enrollment of individuals with End Stage Renal Disease (ESRD) in MA plans by allowing them to choose between MA or fee-for-service plans.2 Enrollment in MA has increased among people with ESRD during the first 2 years of the Cures Act.3However, there is limited information on enrollment rates in MA among these high-need populations, specifically when comparing enrollees with 12-month enrollment to those with any MA enrollment during the year (i.e., between 1 and 12 months). Assessing these two measures simultaneously may reflect changes in insurance preferences, access to care and care quality that may result in switching from MA to fee-for-service. Thus, this study compared the MA enrollment rates of PWD and individuals with ESRD in the US (50 US states and Washington, DC) and Puerto Rico (PR) from 2008 to 2022.
Methods
This observational study utilizes repeated cross-sectional data from the Master Beneficiary Summary File from 2008 to 2022 to identify MA enrollment, current Medicare entitlement, state of residence, and demographic characteristics. The inclusion criteria were full-year Medicare enrollment in the corresponding calendar year and being alive until the end of March 31 of the following year. The MA enrollment rate was calculated based on two criteria: 1) partial-year MA enrollment was defined as having between one and twelve months of MA coverage, including individuals who switched between fee-for-service and MA during the year; 2) full-year MA enrollment was defined as having continuous MA coverage for all twelve months. Standardized differences (d) were calculated to compared characteristics between enrollees who met the inclusion criteria and were residing in either the US and PR in 2022. The study protocol was approved by the [blank] IRB.
Results
Our study included 757,245,942 person-years in the US, and 10,298,906 person-years in PR from 2008 to 2022. Table 1 summarizes the demographic characteristics of all Medicare beneficiaries, who met the inclusion criteria and were residing either in the US and PR for 2022. There were moderate to large differences in MA penetration (d=0.763; 95% CI, 0.760 – 0.765) and enrollment rate (d=0.837; 95% CI, 0.760 – 0.765) between US and PR enrollees in 2022 (See Table 1). In 2022, Medicare beneficiaries in PR exhibited a strikingly higher partial-year MA enrollment rate compared to those in the US (84% vs. 48%). MA enrollment has steadily increased, particularly among PWD and ESRD subpopulations in both, the US and PR (See Figure 1). For the overall MA enrollment rate, the differences observed in the proportion of full-year and partial-year MA enrollment were 2.8% in the US and 1.9% in PR in 2022. However, larger discrepancies were observed among the PWD and ESRD subpopulations in 2022. In the US, the difference between partial-year and full-year MA enrollment rates was 5.7% for PWD and 9.1% for ESRD. In PR, the differences were 2.7% for PWD and 10.0% for ESRD.
Table 1.
Demographic and Geographic Characteristics Comparison between the Medicare Beneficiaries Residing in the United State (US) and Puerto Rico, 2022
| US Mainland N=59749273 | Puerto Rico N=722550 | Standardize Differences (95% Confidence Interval)(a) | |
|---|---|---|---|
| Age, years | 0.220 (0.218–0.223) | ||
| ≤ 65 | 13.38 | 19.70 | |
| 66–75 | 52.69 | 44.10 | |
| 76–85 | 25.84 | 27.31 | |
| ≥ 86 | 8.08 | 8.89 | |
| Female | 54.54 | 54.04 | 0.010 (0.008–0.012) |
| Entitlement(b) | |||
| Disability | 11.95 | 17.83 | 0.166 (0.163–0.168) |
| ESRD | 0.18 | 0.23 | 0.010 (0.008–0.012) |
| Urbanization (c) | 0.430 (0.427–0.432) | ||
| Metropolitan | 82.48 | 93.68 | |
| Adjacent to Metropolitan | 11.88 | 6.27 | |
| Not Adjacent to Metropolitan | 5.65 | 0.05 | |
| MA Penetration at County Level (d) | 0.763 (0.760–0.765) | ||
| ≤ 30% | 22.78 | 0.10 | |
| > 30% | 77.22 | 99.9 | |
| MA Enrollment | 0.837 (0.835–0.839) | ||
| None | 52.37 | 15.78 | |
| Any month in a year | 47.63 | 84.22 |
Note: ESRD: End-Stage Renal Disease; MA: Medicare Advantage.
SAS Macro % stddiff was used to calculate the standardized difference, and Hedges and Olkin 1985 (Hedges LV, Olkin I. Statistical Methods for Meta-Analysis) formula was used to calculate the 95% confidence interval.
The same subject could be qualified for both disability and end-stage renal disease
The Federal Information Processing Standard code, 2023 Rural-Urban Continuum Codes from the US Department of Agriculture
The county-level MA penetration rate was used to describe geographic characteristics
Figure 1. Enrollment Rate of Medicare Advantage Among All Medicare Enrollees in the US Mainland and Puerto Rico Residents by PWD and ESRD.
Note: Partial-year MA enrollment was defined as having between one and twelve months of MA coverage, including individuals who switched between fee-for-Service and MA during the year. Full-year MA enrollment was defined as having continuous MA coverage for all twelve months.
Discussion
Differences between partial-year and full-year MA enrollment among patients with ESRD, may reflect changes in plan choice, access and continuity of care. High poverty rates in PR may make MA plans particularly attractive to high-need beneficiaries due their availability to offer lower premiums and supplemental benefits addressing social determinants of health, as well as the vast majority of dually eligible beneficiaries receiving care through local MA plans, accounting for a high share of MA enrollment.4 However, it is unclear whether differences in MA provider networks and benefit design may further impact disparities in nephrology care for kidney failure patients and access to post-acute rehabilitation in PR compared to the US.5,6 Given the differences in partial-year and full-year MA enrollment among people with ESRD, especially in PR, assessing key factors influencing plan choice and switching, as well as the impact of MA in quality of care and outcomes may be needed.
Takeaway points:
This observational study utilizes repeated cross-sectional data from the 100% Master Beneficiary Summary File from 2008 to 2022 to identify Medicare Advantage enrollment by current Medicare entitlement in the US and Puerto Rico.
Our results indicate growth in MA enrollment in the US mainland and PR, particularly among beneficiaries with PWD and ESRD
PWD and ESRD had a lower 12-month MA enrollment rate compared to beneficiaries with any MA enrollment during the calendar year
Discrepancies between partial-year and full-year MA enrollment among PWD and ESRD subpopulations may reflect changes in plan choice, access to care and care quality
Funding source:
This study was supported by the National Institute on Aging of the National Institutes of Health (K01AG057822; RF1AG078262) and a Research Seed Award from Brown University Office of the Vice President.
Role of the Funder/Sponsor:
The National Institute of Health had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
References
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