Impact of HMO withdrawals on vulnerable Medicare beneficiaries

The Medicare+Choice (M+C) program has faced successive waves of plan withdrawals since 1999. We collected data from 1,055 beneficiaries who were involuntarily disenrolled from a health maintenance organization (HMO) that withdrew from six large markets in 1999 to investigate how they were impacted by the forced change in coverage. Administrative data from this HMO were used to oversample beneficiaries who were perceived to be vulnerable based on their poor health status in the period before the HMO withdrawal. Although most beneficiaries dealt with the withdrawals without major problems, appreciable numbers of beneficiaries did report adverse impacts. These negative impacts were more likely to occur for low-education, low-income, minority beneficiaries. We found little evidence, however, that beneficiaries who were vulnerable due to their poorer health experienced more adverse effects.     

Health care use and expenditures of Medicare HMO disenrollees

We examine the impact of the first wave of Medicare health maintenance organization HMO withdrawals. With data from CMS and United Health Group, we estimate use and expenditure changes between 1998 and 1999 for HMO enrollees who were involuntarily dropped from their plan and returned to fee-for-service (FFS) Medicare using a difference-in-difference model. Compared to those who voluntarily left an HMO, involuntarily disenrolled beneficiaries had higher out-of-pocket expenditures, an 80 percent decrease in physician visits, 38 percent higher emergency room (ER) use and a higher probability of dying. The results suggest beneficiaries face significant costs and reduced health outcomes from unstable Medicare managed care markets.     

Impact of Medicare managed care market withdrawal on beneficiaries

The 2001 Survey of Involuntary Disenrollees was conducted to investigate the impact of Medicare+Choice (M+C) plan withdrawals on Medicare beneficiaries. Eighty-four percent of a total of 4,732 beneficiaries whose Medicare managed care (MMC) plan stopped serving them at the end of 2000 responded to the survey. Their responses indicated that the withdrawal of plans from Medicare affected beneficiaries in terms of concerns about getting and paying for care, increased payments for premiums and out-of-pocket costs, and changes in health care arrangements. Of particular concern were the impacts on those in vulnerable subgroups such as the disabled, less educated, and minorities.     

Consumer information and biased selection in the demand for coverage supplementing Medicare.

This study examines how the relationship between health insurance knowledge and the health status of health insurance consumers influences their decisions to purchase insurance coverage. Data from the federal Medicare health insurance program for the elderly in the United States are used. The basic Medicare program provides a limited amount of coverage for health care services obtained from any provider in the private fee-for-service (FFS) market. Beneficiaries of this program may choose to supplement the basic coverage which they receive by two mechanisms: either they may purchase private insurance designed to fill some of the gaps left by the federal program ('Medigap' policies), thereby remaining in the FFS market and preserving their choice of provider, or they may enroll in health maintenance organizations (HMOs), thereby leaving the FFS market and agreeing to use only those providers affiliated with the HMO, and in return receiving broader coverage at little additional out-of-pocket cost. The study was made possible by a unique data set which combines measures of beneficiary knowledge of Medicare coverage with measures of perceived health status, socio-economic characteristics, and insurance coverage choices for a sample of Medicare beneficiaries who participated in an educational workshop about their insurance coverage options. These data were used to estimate a multinomial logistic model of the determinants of insurance choices, where the options included the two listed above and a basic Medicare option. The study explicitly recognizes the interaction between insurance information and health status in health plan choice. These results show that knowledge of coverage does have a differential impact on the decision to purchase health insurance depending on health status. With a high level of knowledge, sicker beneficiaries are less likely to have basic Medicare alone, compared with HMOs or Medigap policies, while healthier beneficiaries are less likely to be enrolled in HMOs, compared with Medigap policies. This finding has important implications for the use of health status measures to adjust capitated payment formulas when knowledgable consumers have the option to enroll in HMOs or remain in the FFS environment. In the absence of health status adjusters for the HMO capitation payments, high levels of coverage knowledge may exacerbate inherent selection bias among these coverage options by healthier and sicker consumers of health insurance.     

Medigap premiums and Medicare HMO enrollment

OBJECTIVE: Markets for Medicare HMOs (health maintenance organizations) and supplemental Medicare coverage are often treated separately in existing literature. Yet because managed care plans and Medigap plans both cover services not covered by basic Medicare, these markets are clearly interrelated. We examine the extent to which Medigap premiums affect the likelihood of the elderly joining managed care plans. DATA SOURCES: The analysis is based on a sample of Medicare beneficiaries drawn from the 1996-1997 Community Tracking Study (CTS) Household Survey by the Center for Studying Health System Change. Respondents span 56 different CTS sites from 30 different states. Measures of premiums for privately-purchased Medigap policies were collected from a survey of large insurers serving this market. Data for individual, market, and HMO characteristics were collected from the CTS, InterStudy, and HCFA (Health Care Financing Administration). STUDY DESIGN: Our analysis uses a reduced-form logit model to estimate the probability of Medicare HMO participation as a function of Medigap premiums controlling for other market- and individual-level characteristics. The logit coefficients were then used to simulate changes in Medicare participation in response to changes in Medigap premiums. PRINCIPAL FINDINGS: We found that Medigap premiums vary considerably among the geographic markets included in our sample. Measures of premiums from different insurers and for different types of Medigap policies were generally highly correlated across markets. Our models consistently indicate a strong positive relationship between Medigap premiums and HMO participation. This result is robust across several specifications. Simulations suggest that a one standard deviation increase in Medigap premiums would increase HMO participation by more than 8 percentage points. CONCLUSIONS: This research provides strong evidence that Medigap premiums have a significant effect on seniors' participation in Medicare HMOs. Policy initiatives aimed at lowering Medigap premiums will likely discourage enrollment in Medicare HMOs, holding other factors constant. Although the Medigap premiums are just one factor affecting the future penetration rate of Medicare HMOs, they are an important driver of HMO enrollment and should be considered carefully when creating policy related to seniors' supplemental coverage. Similarly, our results imply that reforms to the Medicare HMO market would influence the demand for Medigap policies.     

Designing health insurance information for the Medicare beneficiary: a policy synthesis.

Can Medicare beneficiaries make rational and informed decisions about their coverage under the Medicare program? Recent policy developments in the Medicare program have been based on the theory of competition in medical care. One of the key assumptions of the competitive model is the free flow of adequate information, enabling the consumer to make an informed choice from among the various sellers of a particular product. Options for Medicare beneficiaries in supplementing their basic Medicare coverage include the purchase of private supplementary insurance policies or enrollment in a Medicare HMO. These consumers, in a complex health insurance market, have only limited information available to them because many health plans do not make adequate comparable product information available. Moreover, since the introduction of the Medicare HMO option, the long-range plan for management of the Medicare budget has become based on the large-scale voluntary enrollment of beneficiaries into capitated health plans. The policy instrument that has been used to improve beneficiary decisions on how to supplement Medicare coverage is the informational or educational program. This synthesis presents findings regarding the relative effectiveness of different types of health insurance information programs for the Medicare beneficiary in an effort to promote practical use of the most effective types of information.     

Trends in Medicare health maintenance organization enrollment: 1986-93

This study examines Medicare health maintenance organization (HMO) enrollment under the Tax Equity and Fiscal Responsibility Act (TEFRA) of 1982 (Public Law 97-248) from 1986 to 1993. It shows that there was moderate growth in the number of Medicare beneficiaries participating in the TEFRA risk program, reaching 1 in 20 beneficiaries in 1993. Medicare HMO enrollment is heavily concentrated in a few large plans, resulting in heavy concentrations geographically. California and Florida accounted for over one-third of Medicare HMO enrollees. One-half of the States have no Medicare HMO enrollment and one-fifth of the States have fewer than 15,000 Medicare HMO enrollees.     

Managed care and medical expenditures of Medicare beneficiaries

This paper investigates the impact of Medicare HMO penetration on the medical care expenditures incurred by Medicare fee-for-service (FFS) enrollees. We find that increasing penetration leads to reduced spending on FFS beneficiaries. In particular, our estimates suggest that the increase in HMO penetration during our study period led to approximately a 7% decline in spending per FFS beneficiary. Similar models for various measures of health care utilization find penetration-induced reductions consistent with our spending estimates. Finally, we present evidence that suggests our estimated spending reductions are driven by beneficiaries who have at least one chronic condition.     

Enrollee health status under Medicare risk contracts: an analysis of mortality rates.

Previous studies comparing the health status of Medicare beneficiaries enrolled under HMO risk contracts to that of Medicare beneficiaries in fee-for-service (FFS) have generally focused on demonstration projects conducted before 1985. This study examines mortality rates in 1987 for approximately 1 million aged Medicare beneficiaries enrolled in 108 HMOs. We estimated adjusted mortality ratios (AMR) for each HMO and across all HMOs, by dividing the actual number of deaths among HMO enrollees by the "expected" number of deaths. The expected number of deaths was based on death rates among local FFS populations, adjusting for age, sex, Medicaid buy-in status, and institutional status. The AMR for all HMO enrollees pooled together was 0.80. For persons newly enrolled in 1987, the AMR was 0.69; in general, AMRs were higher for beneficiaries who had been enrolled for longer periods of time. Among individual HMOs, none exhibited an AMR substantially above 1.00. Regression analysis indicated lower AMRs for staff model HMOs than for either IPA or group models. Low mortality among Medicare HMO enrollees is consistent with favorable selection or with improvements in the health status of enrollees due to better access or quality of care in HMOs. In either case, health status differences between HMO enrollees and FFS beneficiaries have implications for the appropriateness of Medicare's Adjusted Average Per Capita Cost (AAPCC) payment formula for HMOs.     

Utilization of Medicare services by beneficiaries having partial Medicare coverage.

With the rapid increases in Medicare expenditures, policymakers are constantly reevaluating the use of and the need for services provided. One approach to better understand these issues is to identify major subgroups of the Medicare population for more detailed evaluation. A disaggregation of the data can pinpoint critical high expenditure areas for further study and may suggest potential cost containment strategies. With funding from the Health Care Financing Administration (HCFA), a series of investigations were designed to study utilization of services by particular types of Medicare beneficiaries. These include: Those who are continuously enrolled in the program over time. Those who died. Those who recently joined Medicare. Those who have one part of Medicare without the other part. This article discusses findings concerning beneficiaries who have only partial Medicare coverage (such as those who are enrolled under one part of Medicare without the other part).     

Selection experiences in Medicare HMOs: pre-enrollment expenditures

Using 1993 and 1994 data, the authors examine whether beneficiaries who enroll in a Medicare health maintenance organization (HMO), including those enrolling for only a short period of time, have lower expenditures than continuous fee-for-service (FFS) beneficiaries the year prior to enrollment. We also test whether biased selection varies by the level of HMO market penetration and the rate of market-share growth. We find favorable selection associated with enrollment into Medicare HMOs, which declines as market share increases but does not disappear. Among short-term enrollees, we find unfavorable selection, however, selection bias was not sensitive to market characteristics.     

Understanding biased selection in Medicare HMOs

OBJECTIVE: To investigate the extent of favorable health maintenance organization (HMO) selection for a longitudinal cohort of Medicare beneficiaries, examine whether the extent of favorable selection varies with the degree of Medicare HMO market penetration in a county, and explain conflicting findings in the literature on favorable HMO selection. DATA SOURCES: A panel of 1992-1996 data from the Medicare Current Beneficiary Survey (MCBS), supplemented with linked data from the Area Resource File and Medicare administrative datasets. STUDY DESIGN: Using random effects probit estimation, we model a beneficiary's HMO enrollment status as a function of self-reported health status and Medicare HMO market penetration. DATA EXTRACTION METHODS: The MCBS data for beneficiaries residing in states served by Medicare HMOs in 1992-1996 were linked by county to the supplementary datasets. PRINCIPAL FINDINGS: We find that favorable selection persists in the cohort over time on some, but not all, measures. We find no substantial association between favorable HMO selection and HMO market penetration. We find that conflicting findings in the literature on favorable HMO selection may be explained by several methodological choices, including the choice of health status measure and the structure of the sample. CONCLUSIONS: Our results support further risk adjustment of the adjusted average per capita cost (AAPCC) payment formula.     

Pre-enrollment reimbursement patterns of Medicare beneficiaries enrolled in "at-risk" HMOs.

The Health Care Financing Administration (HCFA) has initiated several demonstration projects to encourage HMOs to participate in the Medicare program under a risk mechanism. These demonstrations are designed to test innovative marketing techniques, benefit packages, and reimbursement levels. HCFA's current method for prospective payments to HMOs is based on the Adjusted Average Per Capita Cost (AAPCC). An important issue in prospective reimbursement is the extent to which the AAPCC adequately reflects the risk factors which arise out of the selection process of Medicare beneficiaries into HMOs. This study examines the pre-enrollment reimbursement experience of Medicare beneficiaries who enrolled in the demonstration HMOs to determine whether or not a non-random selection process took place. The results of this study suggest that the AAPCC may not be an adequate mechanism for setting prospective reimbursement rates. The Marshfield results further suggest that the type of HMO may have an influence on the selection process among Medicare beneficiaries. If Medicare beneficiaries do not have to change providers to join an HMO, as in an IPA model or a staff model which includes most of the providers in an area, the selection process may be more likely to result in an unbiased risk group.     

Health plan enrollment and mortality in the Medicare program

Prior studies have found that Medicare health maintenance organization (HMO) enrollees have lower mortality (over a fixed observation period) than beneficiaries in traditional fee‐for‐service (FFS) Medicare. We use Medicare Current Beneficiary Survey (MCBS) data to compare 2‐year predicted mortality for Medicare enrollees in the HMO and FFS sectors using a sample selection model to control for observed beneficiaries characteristics and unobserved confounders. The difference in raw, unadjusted mortality probabilities was 0.5% (HMO lower). Correcting for numerous observed confounders resulted in a difference of ?0.6% (HMO higher). Further adjustment for unobserved confounders resulted in an estimated difference of 3.7 and 4.2% (HMO lower), depending on the specification of geographic‐fixed effects. The latter result (4.2%) was statistically significant and consistent with prior studies that did not adjust for unobserved confounding. Our findings suggest there may be unobserved confounders associated with adverse selection in the HMO sector, which had a large effect on our mortality estimates among HMO enrollees. An important topic for further research is to identify such confounders and explore their relationship to mortality. The methods presented in this paper represent a promising approach to comparing outcomes between the HMO and FFS sectors, but further research is warranted. Copyright © 2010 John Wiley & Sons, Ltd.     

Medicare+Choice: an interim report card.

While the aim of Medicare+Choice (M+C) was to expand choice, the choices available to Medicare beneficiaries have diminished since its inception: Existing plans have withdrawn from M+C, few new plans have entered the program from among the newly authorized plan types, greater choice has not developed in areas that lacked choice, and the inequities in benefits and offerings between higher- and lower-paid areas of the country have widened rather than narrowed. Operational constraints probably explain the most immediate declines in M+C enrollment, but Congress's ability to foster success for M+C will ultimately depend on the way in which historical tensions related to competing goals and ideologies for the Medicare program are resolved.     

Issues regarding health plan payments under Medicare and recommendations for reform.

The failures of the market for current Medicare health plans include poor information and price distortions and can be attributed to government policy. Reforms that could improve its structure are annual open enrollment periods, premium rebates from health management organizations (HMOs) to members, and termination of the federal government's subsidy of Medicare supplementary insurance. However, the price for a basic Medicare benefits package would still be distorted because Medicare bases its contribution on the cost of a comparable package in the fee-for-service (FFS) sector rather than on the cost of the most efficient plan available to beneficiaries in each market area. The present Medicare HMO program almost certainly increases total Medicare costs and actually discourages HMO growth by shielding beneficiaries from the true price difference between basic benefits in the HMO and FFS sectors. Lacking payment reforms, the Medicare HMO program should be terminated.     

Comparing mortality and time until death for medicare HMO and FFS beneficiaries

OBJECTIVE: To compare adjusted mortality rates of TEFRA-risk HMO enrollees and disenrollees with rates of beneficiaries enrolled in the Medicare fee-for-service sector (FFS), and to compare the time until death for decedents in these three groups. DATA SOURCE: Data are from the 124 counties with the largest TEFRA-risk HMO enrollment using 1993-1994 Medicare Denominator files for beneficiaries enrolled in the FFS and TEFRA-risk HMO sectors. STUDY DESIGN: A retrospective study that tracks the mortality rates and time until death of a random sample of 1,240,120 Medicare beneficiaries in the FFS sector and 1,526,502 enrollees in HMOs between April 1, 1993 and April 1, 1994. A total of 58,201 beneficiaries switched from an HMO to the FFS sector and were analyzed separately. PRINCIPAL FINDINGS: HMO enrollees have lower relative odds of mortality than a comparable group of FFS beneficiaries. Conversely, HMO disenrollees have higher relative odds of mortality than comparable FFS beneficiaries. Among decedents in the three groups, HMO enrollees lived longer than FFS beneficiaries, who in turn lived longer than HMO disenrollees. CONCLUSIONS: Medicare TEFRA-risk HMO enrollees appear to be, on average, healthier than beneficiaries enrolled in the FFS sector, who appear to be in turn healthier than HMO disenrollees. These health status differences persist, even after controlling for beneficiary demographics and county-level variables that might confound the relationship between mortality and the insurance sector.